Novel Anti-Inflammatory and Analgesic Heterocyclic Amidines that Inhibit Nitrogen Oxide (NO) Production

ABSTRACT

Heterocyclic amidines with anti-inflammatory and analgesic activity that inhibit nitrogen oxide production, of formula (I): 
     
       
         
         
             
             
         
       
     
     in which:
         G 1  and G 2  are hydrogen, halogen, hydroxyl, C 1 -C 4  alkoxy, C 1 -C 4  alkyl, and an amidino substituent of formula Q, provided that, for each compound of formula (I), only one of the two substituents G 1  or G 2  is an amidino substituent of formula Q:       

     
       
         
         
             
             
         
       
     
     and in which the substituents W, Y and X are combined to form 9- or 10-membered bicyclic heteroaromatic derivatives containing up to 2 hetero atoms in the same ring;
     and
       Z is an aryl or heteroaryl group, a linear or branched C 1 -C 6  alkyl or alkenyl chain, a C 1 -C 4  alkyl-aryl group or a C 1 -C 4  alkyl-heteroaryl group.

This is a divisional of application Ser. No. 11/068,347 filed Mar. 1,2005. The entire disclosure of the prior application, application Ser.No. 11/068,347, and priority application T02004A000125 are consideredpart of the disclosure of the accompanying divisional application and ishereby incorporated by reference.

DESCRIPTION

The subject of the present invention are novel heteroaromatic amidinederivatives with anti-inflammatory and analgesic activity,pharmaceutically acceptable salts thereof, methods for preparing thesaid derivatives and formulations thereof, and also their therapeuticuse.

In particular, the present invention relates to the compounds of Formula(I) and to the corresponding pharmaceutically acceptable salts, whichshow marked anti-inflammatory and analgesic activity, both by inhibitingthe production of nitrogen oxide (NO) and by inhibiting the productionof prostaglandins, such as PGE₂, and of cytokines such as interleukin-6(IL-6), and are therefore useful therapeutic agents in the treatment ofpathologies associated with excessive production of NO due to expressionof inducible NOS and of inflammatory prostaglandins produced by COX-2and cytokines such as IL-6.

Among the typical pathologies associated with anomalous production ofNO, prostaglandins and cytokines are: rheumatoid arthritis,osteoarthritis, synovitis, neuropathies, ulcerative colitis and Crohn'sdisease, and inflammatory or atherosclerotic pathologies of thecardiovascular system.

Nitrogen oxide (NO) is a chemical mediator that is widely involved invarious physiological phenomena. At the start of the 1980s it wasdiscovered that the factor with vasodilatory activity released by theendothelium (endothelium-derived relaxing factor, EDRF), which causesacetylcholine-mediated vasodilation, is not other than NO released bythe cells of the vascular endothelium. This discovery was concomitantwith the identification of the metabolic pathway mediated by the enzymeNO synthetase (NOS), which, starting with L-arginine, leads toL-citrulline and NO (Moncada S., Higgs A., N. Engl. J. Med., 1993, 329(27), 2002-12).

Three isoforms of the enzyme NOS have been identified. The isoformshitherto characterized are two constitutive isoforms, known as the typeI or neuronal isoform (nNOS) and the type III or endothelial isoform(eNOS), and an inducible isoform, known as the type II or iNOS isoform.

iNOS is induced after activation, in particular cells, in response to anendotoxin- or cytokine-induced inflammatory stimulus; the control ofiNOS is thus regulated at the level of synthesis of the protein, which,once expressed, produces high concentrations of NO for relatively longtimes.

Macrophages, endothelial cells, endothelial smooth muscle, chondrocytes,osteoblasts and the pulmonary epithelium are particularly effective asregards the expression of iNOS following an inflammatory stimulus.

A noteworthy difference between the constitutive enzymes and theinducible enzyme is thus a delayed but more sustained and longer-lastingproduction of NO mediated by the inducible enzyme, together at the sitewhere this mediator is released. This determines the differences thatgive rise to the NO-mediated physiological or pathophysiologicaleffects.

Thus, whereas NO released from the constitutive enzymes acts as amediator within a signal translation system, for instance the activationof guanylate cyclase by the NO released from the endothelial cells,which, by raising the levels of cGMP, controls the vascular tonus andmuscle relaxation. On the other hand, NO released from the inducibleisoform acts as a cytotoxic molecule, involved in body defencemechanisms (Dugas B. et al.; Res. Immunol. 1995, 146 (9) 664-70).

Thus, whereas, on the one hand, when appropriately regulated, iNOS is anenzyme of fundamental importance for the immune system, imbalances inthe synthesis of iNOS-mediated NO may lead to a whole range ofpathologies involved in inflammatory processes or involving the immunesystem as indicated previously.

It has been demonstrated that iNOS is induced in every species byinflammatory processes and that suppression of its activity is effectivein reducing inflammatory symptomatologies (A. J. Hobbs et al., AnnualReview of Pharmacology and Toxicology, 1999, 39, 191-220).

It is believed, on the one hand, that NO is involved, together withother mediators, in physiological processes of plasticity andreconstitution of bone tissue, whereas, on the other hand, theinvolvement of iNOS-derived NO in the inflammatory process and in thedegeneration of the tissues characterized in rheumatoid arthritis (RA)and osteoarthritis (OA) has been shown (van't Hof R J, Ralston S H.;Nitric oxide and bone, Immunology, 2001 July; 103(3): 255-261).

In point of fact, iNOS has been found in the synovia and cartilage ofpatients suffering from rheumatoid arthritis (RA) and osteoarthritis(OA), and it has been demonstrated that both the synovial cells and thechondrocytes, in vitro, are capable of expressing iNOS by stimulationwith cytokines. In addition, it has been shown that NO is a powerfulstimulator of chondrocyte and synovial cell apoptosis, which wouldexplain the tissue degeneration observed in RA (Armour K J, et al.,Arthritis Rheum. 2001 December; 44(12):2790-6).

The high concentration of NO in patients with ulcerative colitis alsosuggests in this case an involvement of iNOS in this pathology.

With the identification of NO as the critical mediator of a congruousnumber of physiopathological processes, pharmacological control of itsproduction is clearly of therapeutic potential. The first agentsappearing in the literature capable of interfering with the productionof NOS-mediated NO were enzyme inhibitors which were analogues of thesubstrate (L-arginine), among the following: L-NMMA(N^(G)-methyl-L-arginine), L-NNA (N^(G)-nitro-L-arginine), L-NAME(N^(G)-nitro-L-arginine methyl ester), L-NAA (N^(G)-amino-L-arginine)and L-NIO (N^(δ)-iminoethyl-L-ornithine).

On account of their weak selectivity between the various isoforms, theclinical use of these inhibitors requires great care, since inhibitionof the constitutive forms may have serious consequences, such ashypertension and more severe possible effects such as thrombosis andtissue damage. Thus, even though the therapeutic use of sparinglyselective inhibitors is possible, the use of agents capable ofselectively controlling the production of NO from iNOS is of greatertherapeutic potential.

In the last decade, a large number of studies have appeared in theliterature, documenting intense research in this direction (Exp. Opin.Ther. Patents, 1999, 9, 549-556; Exp. Opin. Ther. Patents, 2000, 10,1143-1146); among these, NOS inhibitors of non-amino acid structure havebeen reported, which are for the majority based on bioisosteres of theguanidine group present in the structure of arginine, for instanceS-alkylisothiourea, guanidine and amidine.

All these publications and studies reveal the therapeutic need forpharmacological agents based on modulation of the activity of iNOScharacterized by a better pharmacological profile.

Prostaglandins (PGE) are inflammation mediators generated by the enzymecyclooxygenase (COX). The inducible isoform (COX-2) is overproduced(“upregulated”) in the inflamed tissues and this leads to an increasedsynthesis of PGE.

Interactions exist between NOS and COX systems, and the role of NO ininflammation may therefore depend not only on its direct effect but alsoon its modulatory effect on PGE bio-synthesis.

Interleukin-6 (IL-6) is a cytokine whose overexpression is associatedwith the physiopathology of various human diseases, for instance Crohn'sdisease [see Ho et al., J. Gastroenterol. Suppl. 14, 56-61 (2002)] orrheumatoid arthritis [see Nakahara H. et al.; Arthritis Rheum. 48 (6),1471-4 (2003)].

Since the enzymes iNOS and COX-2, just like the cytokine IL-6, theeffect of which has been discussed above, are expressed in conjunctionwith inflammatory processes, demonstrating large effects in theestablishment and development of the discussed pathologies, it wouldclearly be advantageous to be able to use a medicinal product capable ofexhibiting inhibitory action on the iNOS-mediated production of NO andthe formation of COX-2-mediated inflammatory prostaglandins, not tomention the expression of a cytokine, for instance IL-6.

The compounds of the present invention represented by Formula (I) aretherefore effective in treating pathologies in which there is anappreciable effect of excessive production of NO from iNOS and similarlyconventional NSAIDs in pathologies in which reduction of theinflammatory prostaglandins (e.g.: PGE₂) is pharmacologically useful,for instance in the treatment of arthritis, including but not limited toosteoarthritis, rheumatoid arthritis, neuropathic arthritis and systemiclupus erythematosus.

The compounds of the invention may also be particularly useful, by meansof their inhibitory activity on the production of IL-6, for thetreatment of gastrointestinal pathologies, for instance intestinalinflammations, Crohn's disease and ulcerative colitis. Finally, thecompounds of the present invention may find use in the treatment ofacute or chronic pain of articular or neuropathic origin, in conditionsin which treatment with non-steroidal anti-inflammatory drugs (NSAIDs)or opiate analgesics is indicated.

The compounds of Formula (I) are represented by the following generalformula:

in which:

-   -   G₁ and G₂ are independently selected from hydrogen, halogen,        hydroxyl, C₁-C₄ alkoxy, C₁-C₄ alkyl, and the amidine substituent        of formula Q, provided that, for each compound of formula (I),        only one of the two substituents G₁ or G₂ is the amidine        substituent of formula Q.

The amidine substituent of formula Q is represented by the structuregiven below, in which R is C₁-C₄ alkyl or cycloalkyl.

Amidine substituent of formula Q:

In the compounds of Formula I:

-   -   W is independently: a bond, a substituted or unsubstituted        carbon atom (═CR₁—or ═CH—), an unsubstituted nitrogen atom        (═N—);    -   Y is a substituted or unsubstituted carbon atom (═CR₁— or ═CH—),        or an unsubstituted nitrogen atom (═N—);    -   X is a substituted or unsubstituted carbon atom (═CR₁— or ═CH—),        a substituted or unsubstituted nitrogen atom (—NR₂— or ═N—), a        sulfur atom (—S—) or an oxygen atom (—O—);

provided that: the substituents W, Y and X give rise, suitably incombination, to 9- or 10-membered bicyclic heteroaromatic derivativescontaining up to 2 hetero atoms in the same ring, such as indole,benzofuran, benzothiophene, benzimidazole, benzoxazole, benzothiazole,quinoline, quinoxaline, quinazoline, isoquinoline or cinnolinederivatives.

The substituents R₁ and R₂ are independently selected from hydrogen,C₁-C₄ alkyl, C₁-C₄ alkenyl and C₁-C₄ alkoxy.

The substituents R₃ and R₄ are independently selected from hydrogen,halogen, hydroxyl, C₁-C₄ alkoxy, C₁-C₄ alkyl and C₁-C₄ alkenyl.

Z is an aryl or heteroaryl group, or a linear or branched C₁-C₆ alkyl oralkenyl chain, or a C₁-C₄ alkyl-aryl group or a C₁-C₄ alkyl-heteroarylgroup in which the aryl group is a phenyl which is unsubstituted orsubstituted with one or more substituents independently selected fromhalogen, trifluoromethyl, hydroxyl, nitro, cyano, carboxyl, carboxamido,carbonyl, thio, methylthio, methanesulfonyl, methanesulfinyl,sulfonamido, trifluoromethoxy, C₁-C₆ alkoxy and C₁-C₆ alkyl, and theheteroaryl group is a 5- or 6-atom heteroaromatic ring containing one ormore hetero atoms, which is unsubstituted or substituted with one ormore substituents independently selected from halogen, trifluoromethyl,hydroxyl, nitro, cyano, carboxyl, carbonyl, thio, methylthio,methanesulfonyl, methanesulfinyl, trifluoromethoxy, C₁-C₆ alkoxy andC₁-C₆ alkyl.

The C₁-C₄ alkyl-aryl group is a linear or branched, saturated orunsaturated C₁-C₄ hydrocarbon chain substituted with an aryl group. Whenthe C₁-C₄ chain is unsaturated, it is intended to contain only onesubstituted or unsubstituted double bond. Substituents for the arylgroup are independently selected from the groups defined above assubstituents for the aryl group.

The C₁-C₄ alkyl-heteroaryl group is a linear or branched, saturated orunsaturated C₁-C₄ hydrocarbon chain substituted with a substituted orunsubstituted heteroaryl group. When the C₁-C₄ chain is unsaturated, itis intended to contain only one substituted or unsubstituted doublebond.

The term “heteroaryl” means any of the heterocyclic nuclei definedabove.

The compounds of formula (I) may thus be used either in free base formor as pharmaceutically acceptable salts. The present invention thusincludes all the pharmaceutically acceptable salts of the compounds offormula (I). Pharmacologically acceptable salts of the compounds offormula (I) include, but are not limited to: hydrochloride,hydrobromide, sulfate, hydrogen sulfate, methanesulfonate, maleate,citrate, fumarate and succinate.

Pharmaceutical formulations of the compounds of the invention may beprepared using conventional techniques. The formulations include thosesuitable for oral, parenteral (including subcutaneous, intramuscular,intravenous, intra-articular and transdermal), topical or rectal use orother forms suitable for obtaining the desired therapeutic effect, forexample delayed-action solid formulations for oral use allowing a slowrelease of the active principle over time.

Substances commonly used in the pharmaceutical field, such asexcipients, binders, disintegrants and substances capable of stimulatingtransdermal or mucosal absorption, may be used together with the activeprinciple in the pharmaceutical formulations.

Table 1 below, which is non-limiting, illustrates a number of compoundsof formula (I) that are the subject of the present invention.

TABLE 1 Examples of compounds of formula (I) Com- pound Structure G₁ G₂W Y X Z 1

Acetamidine H Bond S N Ph 3

Acetamidine H Bond S N 4-Cl-Ph 4

Acetamidine H Bond S N n-Pentyl 5

Acetamidine H Bond CH NH Ph 6

Acetamidine H Bond CH NMe Ph 8

Acetamidine H CH CH N Ph 9

H Acetamidine Bond S N Ph 10

H Acetamidine Bond S N Ph 11

H Acetamidine Bond S N Benzyl 12

H Acetamidine Bond S N Styryl 13

H Acetamidine Bond S N 2-MeO-5- SO₂NH₂-Ph 14

H Acetamidine Bond S N 2-pyridyl 15

H Acetamidine Bond S N 4-MeO-Ph 16

H Acetamidine Bond S N 2.4-(MeO)₂- Ph 17

H Acetamidine Bond S N 3-MeO-Ph 18

H Acetamidine Bond S N 2-Me-Ph 19

Acetamidine H Bond N NH 4-F-Ph 20

Acetamidine H Bond N NH 4-Cl-Ph 21

Acetamidine H Bond N NH Ph 22

Acetamidine H Bond N NH n-pentyl 23

Acetamidine H Bond N NH 2-pyrrol 25

Acetamidine H Bond N NH 4-CO₂Me-Ph 26

Acetamidine H Bond N NH 4-CO₂H-Ph 27

Acetamidine H CH N N Ph 28

Acetamidine H Bond CH O Ph 29

H Acetamidine Bond O NH Ph 30

H Acetamidine Bond O NH 4-ClPh 31

H Acetamidine Bond O NH 3-CF₃Ph 32

H Acetamidine Bond O NH 4-CF₃Ph 33

H Acetamidine Bond O NH 2-FPh 34

H Acetamidine Bond O NH 3,4-ClPh 35

H Acetamidine Bond N NH 3,4-ClPh 36

H Acetamidine Bond N NH 3-CF₃Ph 37

H Acetamidine Bond N NH 2-OMePh 38

H Acetamidine Bond N NH 2-FPh 39

H Acetamidine Bond N NH 2-MePh 40

Acetamidine H Bond S N 2-pyrrol 41

H Bond S N 2-Ph 42

Acetamidine H Bond O NH Ph 43

H Acetamidine Bond NR N 2-MeO-Ph 44

H Acetamidine Bond N NR 2-MeO-Ph

According to a further aspect of the present invention, the processrequired for preparing the compounds of formula (I) is described.

The compounds of the invention are prepared from a compound of formula(II) by reaction with a compound of formula (III).

in which W, Y, X, Z, R₃ and R₄ are defined as for the compounds offormula (I), while G′₁ and G′₂ are independently selected from:hydrogen, halogen, hydroxyl, C₁-C₄ alkoxy, C₁-C₄ alkyl, and the aminegroup (—NH₂), provided that, for each compound of formula (II), only oneof the substituents G′₁ or G′₂ is an amine group (—NH₂).

in which R is as defined for the amidino substituent of formula Q and Lis a leaving group. The leaving group L is an alkoxy group (ethoxy ormethoxy), or an alkylthio group (RS—; thiomethyl or thiomethylnaphthyl)or an arylthio group (Ar—S; thiophenyl).

Optionally, the following steps can complete the conversion of acompound of formula (II) into a compound of formula (I):

-   -   removal of any protecting group present    -   conversion of the product into the corresponding salt or        solvate.

The reaction of a compound of formula (II) with a compound of formula(III) may be performed in a suitable solvent such as: alcohol,acetonitrile, N,N-dimethylformamide (DMF) or tetrahydrofuran (THF), attemperatures of between 0° C. and 50° C., as described in the case ofalkoxy-imidates (Cereda et al., J. Med. Chem., 1990, 33, 2108-2113) orin the case of thioimidates (Collins et al., J. Med. Chem., 1998, 41,2858-2871; Miosokowski et al., Synthesis, 1999, 6, 927-929; J. Eustacheet al. Tetrahedron Letters, 1995, 36, 2045-2046, or Shearer et al.,Tetrahedron Letters, 1997, 38, 179-182).

The compounds of formula (III) are commercially available or may beprepared as described in the given references.

The compounds of formula (II) are obtained from compounds of formula(IV):

in which W, Y, X, Z, R₃ and R₄ are as defined above for the compounds offormula (I), N₁ and N₂ are independently selected from: hydrogen,halogen, hydroxyl, C₁-C₄ alkoxy, C₁-C₄ alkyl, nitro group (NO₂), orprotected amine group (e.g. carbamate or amide), or a suitable precursorof an amine group, for instance a carboxyl (COOH) or a derivativethereof (acyl chloride, ester or primary amide), provided that, for eachcompound of formula (IV), only one of the substituents N₁ or N₂ is anitro group or a protected amine group, or a suitable precursor thereofas defined above. Suitable protecting groups for the amine groupinclude: t-butoxycarbonyl (BOC), benzyloxycarbonyl (Z), trifluoroacetyl,acetyl and benzoyl.

When N₁ or N₂ is a nitro group, the compounds of formula (II) areobtained by reducing a compound of formula (IV). The reduction may beperformed either using hydrogen and a catalyst (Pd/C or PtO₂), accordingto the usual methods of organic chemistry (P. Rylander, CatalyticHydrogenation in Organic Synthesis, Academic Press, 1979), or usingchemical reducing agents, for instance stannous chloride (F. D. Bellamyet al., Tetrahedron Letters, 1984, 25 (8), 839-842.), iron (C. A.Merlic, JOC, 1995, 33-65), nickel boride (Atsuko Nose, Chem. Pharm.Bull., 1989, 37, 816-818), Raney nickel/propanol (Kuo E., SyntheticCommunication, 1985, 15, 599-6023) or sodium borohydride and Pd/C(Petrini M., Synthesis, 1987, 713-714).

When N₁ or N₂ is a protected amine group, the compounds of formula (II)may be obtained from a compound of formula (IV) by removal of theprotecting group, according to methods known in organic chemistry (T. W.Green and P. Wuts, Protective Groups in Organic Synthesis, 1991, J.Wiley & Sons).

When N₁ or N₂ is a carboxyl group (COOH), the conversion of a compoundof formula (IV) into a compound of formula (II) may be performed viaSchmidt or Curtius degradation (H. Wolff, Organic Reactions, 1946.3,307; J. Saunders, Chem. Rev. 1948, 43, 203).

The compounds of formula (IV) are commercially available or may beprepared from compounds of formula (V):

in which:

a) W, Y, X, Z, R₃ and R₄ are as defined for the compounds of formula (I)and P₁ and P₂ are independently selected from hydrogen, halogen,hydroxyl, C₁-C₄ alkoxy and C₁-C₄ alkyl, provided that, for each compoundof formula (V), at least one of the substituents P₁ or P₂ is a hydrogenatom. In this case, the compounds of formula (IV) may be obtained byaromatic nitration of a compound of formula (V) and, where applicable,by separation of the desired product from the correspondingregioisomers.

b) W, Y, X, R₃ and R₄ are defined as for the compounds of formula (I), Zis a halogen or hydrogen, and P₁ and P₂ are independently selected fromgroups as defined in a) and also nitro, amine and protected amine,provided that, for each compound of formula (V), only one of thesubstituents P₁ or P₂ is a nitro group, an amine group or a protectedamine group. In this case, a compound of formula (V) may be convertedinto a compound of formula (IV) in which Z is aryl or heteroaryl viaformation of an aromatic-aromatic bond according to standard methods oforganic chemistry (from J. Hassan, Chem. Rev., 2002, 102, 1359-469);when, in the compounds of formula (IV), Z is an aryl or heteroarylgroup, the compounds of formula (V) are converted into compounds offormula (IV), using the coupling of an aryl-zinc with a suitable halideor the Stille reaction of the appropriate stannane with thecorresponding halide.

When, in the compounds of formula (V), Z is halogen, and, in thecompounds of formula (IV), Z is an aryl or heteroaryl group, thecorresponding conversion may be performed by using the coupling of zincderivatives with aromatic or heteroaromatic halides (Scheme 1).

According to this method, the compounds of formula (V), in which Z is Hor halogen, are reacted with n-butyllithium or t-butyllithium, theresulting organolithium derivative (Va) is reacted with zinc chloride togive the corresponding organozinc reagents (Vb), which are reacted withthe aryl or heteroaryl halide, via homogeneous catalysis (palladium), toform the compounds of formula (IV).

The reaction conditions are equivalent to those reported (M. Amat etal., J. Org. Chem., 1997, 62, 3158 and S. Hargreaves et al., TetrahedronLetters, 2000, 41, 1653). Alternatively, the intermediates (Vb,Scheme 1) may be obtained directly from the compounds of formula (V) byoxidative addition of zinc metal (Knochel et al., Tetrahedron Lett.,1990, 31, 4413; Yamanaka et al., Tetrahedron, 1993. 49, 9713).

Alternatively, the compounds of formula (IV) are obtained from compoundsof formula (V) in which Z is halogen (Scheme 1) by reaction with an arylor heteroaryl zinc derivative, using methods identical to thosementioned previously.

Alternatively (Scheme 2), when, in the compounds of formula (V), Z ishydrogen or halogen, and, in the compounds of formula (IV), Z is an arylor heteroaryl group, the conversion of (V) into (IV) may be performedvia cross-coupling catalysed by Pd stannanes with aryl or heteroarylhalides, according to the Stille method. The compounds of formula (V) inwhich Z is halogen are converted into the corresponding arylstannanes(Vb) according to known methods (Pereyere M., Tin in Organic Synthesis,Butterworths, 1987), i.e. by reacting a compound of formula (V) in whichZ is halogen with hexamethylditin, usingtetrakis(triphenylphosphine)palladium (0) as catalyst, in refluxing THF(J. La Voie, J. Org. Chem., 2000, 65, 2802-2805) or by reaction withhexabutylditin using the same catalyst, in toluene as solvent (K.Masanori et al., Bull. Chem. Soc. Jpn, 1983, 56, 3855-3856). This methodis particularly effective when, in the compounds of formula (V), P₁ orP₂ is a nitro group or in which other substituents do not support thepresence of bases and/or nucleophiles such as alkyllithiums.

Alternatively (Scheme 2), the compounds of formula (IV) may be obtainedfrom compounds of formula (V) in which Z is halogen or hydrogen byreaction with an organolithium (n-butyllithium or t-butyllithium). Inthis case, the compounds of formula (V) give the correspondingderivatives (Va), which are reacted with trimethyltin chloride ortri-n-butyltin chloride to give the corresponding stannanes (Vb). Theseintermediates are reacted with suitable aromatic or heteroaromatichalides, under palladium catalysis, to give the compounds of formula(IV). The conversion of compounds of formula (V) into compounds offormula (Vb) may be performed using known procedures (P. Jutzi, J.Organometallic Chem., 1983, 246, 163-168). The coupling of the stannanes(Vb) with aromatic or heteroaromatic halides is performed according tostandard procedures (P. Gros, Synthesis, 1999, 5, 754-756).

Alternatively, the compounds of formula (IV) are obtained from compoundsof formula (V) in which Z is halogen (Scheme 2), via palladium-catalysedcoupling with an aryl or heteroaryl stannane, using the methodsdescribed above, the preferred route depending on the compatibility ofthe substituents present.

Alternatively (Scheme 3), the compounds of formula (IV) in which Z isaryl and heteroaryl may be obtained from compounds of formula (V), inwhich Z is hydrogen or halogen, via Suzuki coupling of boronicderivatives with the corresponding halides. This palladium-catalysedreaction for formation of the aryl-aryl bond using arylboronic orheteroarylboronic derivatives is a known process (J. Hassan, 2002, ChemRev., 102, 1359-1469).

In this case, compounds of formula (V), in which Z is hydrogen orhalogen, are converted into the boronates (Vb) by reaction with analkyllithium or lithium diisopropylamide to form the intermediates (Va),which are converted into the boronates (Vb) by reaction with trimethylor triisopropyl borate according to standard procedures (A. Alvarez, J.Org. Chem., 1992, 57, 1653-1656, ∘ J. G. Grieb, Synthetic Commun., 1995,25, 214-2153).

The palladium-catalysed coupling of the intermediates (Vb), boronicacids or esters, with suitable aryl halides gives the compounds offormula (IV), according to known procedures (B. Maes et al.,Tetrahedron, 2000, 56, 1777-1781).

Alternatively, the compounds of formula (IV) are obtained from thecompounds of formula (V) in which Z is halogen (Scheme 3) via Suzukicoupling with an aryl or heteroaryl boronic derivative, using the samemethods as mentioned above.

Alternatively (Scheme 4), the compounds of formula (IV) in which W, Y,X, R₃ and R₄ are defined as for the compounds of formula (I), Z is alinear or branched C₁-C₆ chain, a C₁-C₄ alkylaryl group or a C₁-C₄alkylheteroaryl group, P₁ and P₂ are as defined in point (b), and areobtained from the esters of formula (V) via Heck synthesis. In thiscase, the compounds of formula (V) in which Z is a suitable halogen areconverted into compounds of formula (IV) in which Z is a linear orbranched C₁-C₆ alkenyl chain, a C₁-C₄ alkenylaryl group or a C₁-C₄alkenylheteroaryl group via palladium-catalysed arylation of a terminalolefin (Heck reaction). The resulting olefins may constitute per secompounds of formula (IV) or may be converted (reduction reaction of theolefin to a saturated hydrocarbon) into compounds of formula (IV) inwhich Z is a linear or branched C₁-C₆ alkyl chain, a C₁-C₄ alkylarylgroup or a C₁-C₄ alkylheteroaryl group. The Heck reaction is performedaccording to known procedures (R. F. Heck, Org. React., 1982, 27,345-390). In the case where the compound of formula (IV) thus obtained,in which Z is a linear or branched, unsaturated C₁-C₆ chain, needs to beconverted into a compound of formula (IV) in which Z is a saturatedC₁-C₆ chain, via catalytic hydrogenation, common techniques are used (P.Rylander, Catalytic Hydrogenation in Organic Synthesis, Academic Press,1979).

c) Alternatively (Scheme 5), the compounds of formula (IV), in which: W,Y, X, Z, R₃ and R₄ are as defined for the compounds of formula (I), P₁and P₂ are as defined in point (b), are prepared by reaction of acompound of formula (VI) with a compound of formula (VII). In the casewhere, for the compounds of formula (VI), P₁ and P₂ are as definedabove, W is a bond or a substituted or unsubstituted carbon atom, asdefined previously. Y is a thiol group (SH), a hydroxyl group (OH), anunsubstituted nitrogen atom, (—NH₂) or a triphenylphosphonium groupP⁺(Ph)₃, X is a substituted or unsubstituted nitrogen atom (—NH₂ or—NHR₂), a thiol group (—SH) or a hydroxyl group (—OH).

For the compounds of formula (VII), Z is as defined for the compounds offormula (I), J is an oxygen atom (O) or a nitrogen atom (N) and T ishydroxyl, hydrogen, halogen, amine or C₁-C₄ alkoxy.

Non-limiting examples of the synthetic route (c) are given in Scheme 6below:

The compounds of formula (VI), like the compounds of formula (VII), arecommercially available or may be prepared from commercially availablecompounds according to known procedures. In the case of Scheme 6a, the2-substituted benzothiazoles are obtained from the acids of formula(VII) and from the appropriate aminothiophenols of formula (VI) byreaction with polyphosphoric acid (PPA) (D. Boger, J. Org. Chem., 1978,43, 2296-2297; or D. W. Hein et al., J. Am. Chem. Soc., 1957, 427-429).Esters, imidates or amides of formula (VII) may be used as alternativesto the acids reported in Schemes 6a and 6c. Alternatively, the2-substituted benzothiazoles are obtained from the aldehydes of formula(VII) (Scheme 6b) by reaction with suitable aminothiophenols, catalysedby pyridinium p-toluenesulfonate (PTS) or iron (III) chloride (Chem.Pharm. Bull., 1998, 46, 623-630).

In the case of Scheme 6c, the 2-substituted benzoxazoles are obtainedfrom the respective acids of formula (VII) or derivatives (acylchlorides, esters, ortho esters, imidates or amides) and from theappropriate aminophenols of formula (VI) by reaction with PPA (J. P.Heeschen in Journal Org. Chem., 1997, 62, 3552-3561).

The benzoxazoles, Scheme 6c, are also obtained by reaction ofaminophenols with the acyl chlorides of formula (VII) in toluene, andthe corresponding amides thus formed are cyclized into benzoxazoles,thermally or via acid catalysis (p-toluenesulfonic acid) (R. P. Perry etal., Journal Org. Chem., 1992, 57, 2883-2887), or by POCl₃-mediatedcyclization.

In the case of Scheme 6d, the 2-substituted benzimidazoles are obtainedby PPA-mediated reaction of the respective acids of formula (VII) andthe phenylenediamines of formula (VI) (C. M. Orlando et al., J. Org.Chem., 1970, 35, 3147-3148). Alternatively, the 2-substitutedbenzimidazoles are obtained from the aldehydes of formula (VII) bycondensation of the corresponding bisulfite adduct withphenylenediamines (M. A. Weidner et al., Bioorganic & Medicinal Chem.Lett., 2001, 1545-1548).

Finally, the 2-substituted benzimidazoles, Scheme 6d, are obtained byreaction of the phenylenediamines of formula (VI) with the acylchlorides corresponding to the acids of formula (VII), and the amidesare then cyclized into the corresponding benzimidazoles as describedabove for the benzoxazoles. In the case of Scheme 6e, the appropriate2-substituted quinazolines are obtained by acylation of the amines (VI)with the benzoic acids (VII), followed by POCl₃-mediated cyclization (A.Downes, in J. Chem Soc., 1950, 3053-3055), and the synthesis iscompleted by oxidation with DDQ or chloranil; the procedure described byJ. Van den Eynde, Synthesis, 1993, 867-869 may be used as analternative.

In the case of Scheme 6f, the benzofuran derivatives of formula (IV) areprepared by reaction of the corresponding phosphoranes, obtained fromthe phosphonium salts of formula (VI) and from the acyl chlorides offormula (VII). In the case of Scheme 6g, the benzothiophene derivativesof formula (IV) are prepared by reaction of the correspondingphosphoranes obtained from phosphonium salts of formula (VI) and fromthe acyl chlorides of formula (VII)(A. Arnoldi, M. Carughi., Synthesis,1988, 155-157).

d) Alternatively (Scheme 7), the compounds of formula (IV) in which: W,Y, X, Z, R₃ and R₄ are as defined for the compounds of formula (I), andP₁ and P₂ are as defined in point (b), are prepared by cyclizationreaction of a compound of formula (XIII). The compounds of formula(XIII) are prepared by reaction of a compound of formula (XII) with thecompounds of formula (XI). In the case where, for the compounds offormula (XI), P₁ and P₂, R₃ and R₄ are as defined above, X is a hydrogenatom, a nitrogen atom, a carboxylate group (COOH) or a derivativethereof, or an aldehyde group (CHO); T is a halogen or a sulfur atom. Inthe compounds of formula (XIII), W is a sulfur atom, a substitutedcarbon atom (—CR₁═) or an unsubstituted carbon atom (—CH═) belonging toan olefinic or acetylenic system; Y is a substituted or unsubstitutedcarbon atom and Z is defined as for the compounds of formula (I).

Representative examples of conversion of compounds of formula (XI) intocompounds of formula (IV) are given in Scheme 8.

In Scheme 8a), the 2-iodobenzoic derivative, a compound of formula (XI),is converted into the acetylenic derivative of formula (XIII), via aHeck reaction (R. C. Larock et al., Journal Org. Chem., 2003, 68, 5936).The compound of formula (XIII) is then cyclized into the isocoumarin,which, by reaction with methanolic ammonia, is converted into thecorresponding isoquinolinone; the isoquinolinone is converted into thecompound of formula (IV) via known methods, for example by conversion to1-chloroisoquinoline, followed by reductive dehalogenation.

As reported in Scheme 8b), the 2-bromoaniline of formula (XI) isreacted, under Heck conditions, with styrene or with a substitutedstyrene to give the compounds of formula (XIII) in which W and Y areboth carbon atoms forming part of an olefinic bond. The cyclization ofthe compound of formula (XIII) into the compound of formula (IV) isperformed via catalysis with Pd (J. LaVoie, Bio-organic & MedicinalChem., 1996, 4, 621-630).

The following non-limiting examples describe the details of thesynthesis of the amidine derivatives of formula (I):

Examples of Preparation of Compounds of Formula (I) According toSynthetic Route (a):

EXAMPLE 1 Compound 1 N-(2-phenylbenzothiazol-6-yl)acetamidine

Triethylamine (36.7 ml, 0.263 mol) is added to methyl acetamidatehydrochloride (28.85 g, 0.263 mol) in acetonitrile (600 ml). The mixtureis stirred at room temperature for 15 minutes and2-phenyl-6-aminobenzothiazole (29.8 g, 0.131 mol) is added. Theresulting mixture is stirred for 72 hours at room temperature, the solidis filtered off, suspended in ethyl acetate and basified with 1M NaOH(pH=10), and the phases are separated. The organic phase is washed withwater, dried and evaporated. The solid is recrystallized from isopropylether. Yield: 14.5 g (42%); Elem. anal. C₁₅H₁₃N₃S; theory: C:67.39H:4.90 N:15.72; found C:66.78 H:5.03 N:15.60; IR (KBr): 3260, 3020,1645, 1590 cm⁻¹; ¹H-NMR (d₆-DMSO) 8.05 (m, 2H); 7.9 (d, 1H); 7.35-7.55(m, 3H); 6.95 (m, 1H); 5.9-6.2 (broad s, 2H); 1.8 (m, 3H).

1a) 2-phenyl-6-aminobenzothiazole

2-Phenyl-6-nitrobenzothiazole (73.5 g, 0.286 mol) is added to tindichloride (200.74 g, 0.89 mol) in 37% HCl (300 ml). The mixture isheated at 100° C. for 40 minutes. The resulting mixture is cooled andaqueous ammonia (pH=10) is added dropwise. The product is extracted withchloroform and the extracts are concentrated. The solid isrecrystallized from isopropyl ether/hexane (2/1). Yield: 29.9 g (46%);Rf (9/1 chloroform/methanol): 0.68; m.p.: 199.8-201.1° C.; IR (KBr):3450, 3305, 3190, 1619 cm⁻¹.

1b) 2-phenyl-6-nitrobenzothiazole

2-Phenylbenzothiazole (Aldrich, 63.89 g, 0.302 mol) is nitrated with100% nitric acid (190 ml, 4.53 mol) at 5° C. The mixture is stirred at5° C. for 70 minutes, quenched in ice-water and basified with 32% NaOH(pH=10). The product is filtered off and the solid obtained is suspendedin water and filtered off. The product is recrystallized from isopropylether. Yield: 73.6 g (95%); Rf (8/2 petroleum ether/ethyl acetate):0.76; m.p.: 178.9-181.3° ; ¹H-NMR (d₆-DMSO): 9.16 (d, 1H); 8.35 (dd,1H); 8.23 (d, 1H); 8.15 (dd, 1H) 7.58; (m, 4H).

EXAMPLE 2 Maleate of Compound 1-Compound 2N-(2-phenylbenzothiazol-6-yl)acetamidine maleate

A 1M solution of maleic acid in acetone (10 ml) is added dropwise toN-(2-phenylbenzothiazol-6-yl)acetamidine (1 g, 0.00374 mol) (Example 1),in acetone (30 ml). The product is precipitated and filtered off. Yield:1.09 g (77%); Elem. anal. C₁₅H₁₃N₃S.C₄H₄O₄; theory C:59.51 H:4.47N:10.96; found C:59.30 H:4.36 N:10.62; IR (KBr): 3060, 1700, 1480, 1360cm⁻¹.

EXAMPLE 3 Compound 3 N-[2-(4-chlorophenyl)benzothiazol-6-yl]acetamidine

Prepared in a manner similar to that of Example 1. Yield: 40%; Elem.anal. C₁₉H₁₇N₃O₄S; M.W.: 383.419; theory C:59.70 H:4.00 N:13.92; foundC:59.29 H:3.70 N:13.63; IR (KBr): 3450, 3290, 3115, 1640 cm⁻¹; ¹H-NMR(d₆-DMSO): 8.2 (d, 2H); 7.9 (m, 1H); 7.6 (d, 2H); 7.4 (m, 1H); 6.9 (m,1H); 6.3 (broad s, 2H); 1.9 (m, 3H).

3a) 2-(4-chlorophenyl)-6-aminobenzothiazole

Prepared in a manner similar to that of Example 1a. Yield: 77%; Rf (8/2hexane/ethyl acetate): 0.16; m.p.: 165.9-168° C.; Elem. anal.C₁₃H₉ClN₂S; theory C:59.88 H:3.48 N:10.74; found C:59.22 H:3.34 N:10.84;IR (KBr): 3460, 3355, 3195, 1620 cm⁻¹.

3b) 2-(4-chlorophenyl)-6-nitrobenzothiazole

Prepared in a manner similar to that of Example 1b from2-(4-chlorophenyl)benzothiazole, which is prepared in a manner similarto that of Example 4c. Yield: 84%; Rf (3/7 chloroform/toluene): 0.50;m.p.: 227.2-232° C.; IR (KBr): 1515, 1340 cm⁻¹; ¹H-NMR (d₆-DMSO): 9.16(d, 1H); 8.35 (dd, 1H); 8.23 (d, 1H); 8.15 (dd, 1H); 7.58 (m, 4H).

EXAMPLE 4 Compound 4 N-(2-pentylbenzothiazol-6-yl)acetamidine

Triethylamine (16.6 ml, 0.119 mol) is added to methyl acetamidatehydrochloride (5.58 g, 0.051 mol) in acetonitrile (100 ml). The mixtureis stirred at room temperature for 15 minutes, and2-pentyl-6-aminobenzothiazole(hydrochloride) (8.9 g, 0.034 mol) isadded. The resulting mixture is stirred at room temperature for 48hours, filtered and evaporated. The residue is taken up in ethyl acetateand the product is extracted with 0.1M HCl. The aqueous phases arecombined, basified with NaOH (pH=10) and extracted with ethyl acetate.The extracts are washed with water. The resulting organic phase isdried, filtered and evaporated. The solid is recrystallized fromisopropyl ether. Yield: 5.0 g (56%); Elem. anal. C₁₄H₁₉N₃S; M.W.:261.39; theory C:64.33 H:7.32 N:16.07; found C:64.42 H:7.48 N:16.13; IR(KBr): 3318, 3085, 1655, 1615, 1586 cm⁻¹ _(;) ¹H-NMR (d₆-DMSO) 7.7 (d,1H); 7.3 (m, 1H); 6.8 (m, 1H); 6.1 (m 2H); 3 (t, 2H); 2-0.7 (m, 12H).

4a) 2-pentyl-6-aminobenzothiazole hydrochloride

10% Pd/C (0.88 g) is added to 2-pentyl-6-nitrobenzothiazole (10.3 g,0.041 mol) in methanol (250 ml). The mixture is hydrogenated, thecatalyst is filtered off and the filtrate is evaporated. The residue istaken up in methanol, isopropyl ether/HCl is added and the hydrochlorideis precipitated. Yield: 9.29 g (89%); Rf (95/5 methylenechloride/methanol): 0.75; IR (KBr): 3465, 3395, 2955, 1505, 1455, 1155,810 cm⁻¹.

4b) 2-pentyl-6-nitrobenzothiazole

2-Pentylbenzothiazole hydrochloride (20.5 g, 0.084 mol) is added, at 0°C., to trifluoromethanesulfonic acid (44.6 ml 0.504 mol) and 100% nitricacid (10.6 ml, 0.215 mol) in methylene chloride (270 ml), and themixture is stirred at 0° C. for 1.5 hours and at room temperature forone hour. Water (150 ml) is added dropwise and the phases are separated.The organic phase is washed with 0.5M NaHCO₃ and with water. Theresulting solution is dried, filtered and concentrated. The solidobtained is recrystallized from petroleum ether. Yield: 10.6 g (50%); Rf(8/2 petroleum ether/ethyl acetate): 0.71; ¹H-NMR (d₆-DMSO) 9.05 (d,1H); 8.25 (dd, 1H); 8.15 (d, 1H); 3.13 (t, 2H); 1.28-1.36 (m, 4H); 0.85(t, 3H).

4c) 2-pentylbenzothiazole hydrochloride

PPA (140 g) is added to hexanoic acid (25.06 ml, 0.2 mol) and2-mercaptoaniline (21.84 ml, 0.2 mol). The mixture is heated at 120° C.for 30 minutes. The resulting mixture is cooled and water (200 ml) isadded dropwise, followed by addition of 32% NaOH (pH=10). The resultingmixture is extracted with ethyl acetate and washed with water. Theresulting solution is dried and evaporated, the residue is taken up inmethanol, isopropyl ether/HCl is added and the hydrochloride isprecipitated. Yield: 43.8 g (90%); Rf (8/2 petroleum ether/ethylacetate): 0.78; m.p.: 106.6-109.0° C.; IR (KBr): 30.75, 2925, 2210,1884, 1440, 775 cm⁻¹.

EXAMPLE 5 Compound 5 N-(2-phenyl-1H-indol-5-yl)acetamidine

Prepared in a manner similar to that of Example 1. Yield: (63%); Elem.anal. C₁₆H₁₅N₃ M.W.: 249.31; theory C:77.08 H:6.06 N:16.85; foundC:76.97 H:6.29 N:16.85; IR (KBr): 3434, 3024, 1634, 1597 cm⁻¹ _(;)¹H-NMR (d₆-DMSO) 7.8-6.3 (m, 9H); 1.8 (s, 3H).

5a) 2-phenyl-5-amino-1H-indole

Prepared in a manner similar to that of Example 4a. Yield: (83%); Rf(2/1 hexane/ethyl acetate): 0.30; m.p.: 220.2-220.5° C. Elem. anal.C₁₄H₁₂N₂; theory C:80.74 H:5.81 N:13.45; found C:80.55 H:5.76 N:13.35;IR (KBr): 3416, 3036, 1622, 1585 cm⁻¹.

5b) 2-phenyl-5-nitro-1H-indole

This intermediate is prepared by nitration of 2-phenylindole (6 g, 31mmol) with NaNO₃ (2.8 g, 33 mmol) in 97% H₂SO₄ (200 mL) at 5° C. Yield:6.9 g (93%); m.p.: 198.7-200° C. (lit. 201-203° C.; Wayland, E. N. etal. J.O.C. 1966, 65).

EXAMPLE 6 Compound 6 N-(1-methyl-2-phenyl-1H-indol-5-yl)acetamidine

Prepared in a manner similar to that of Example 1. Yield: 68%; Elem.anal. C₁₇H₁₇N₃; theory C:77.54 H:6.51 N:15.96; found C:76.77 H:6.83N:15.65; IR (KBr): 3441, 3013, 1634, 1597 cm⁻¹; ¹H-NMR (d₆-DMSO)7.90-7.20 (m, 6H); 6.90 (d, J=1.5 Hz, 1H); 6.60 (dd, J=8.6 Hz, 1.5 Hz,1H); 6.40 (s, 1H); 5.90 (bs, 2H, exch. D₂O); 3.75 (s, 3H); 1.8 (s, 3H).

6a) 5-amino-2-phenyl-1-methylindole

Prepared in a manner similar to that of Example 4a. Yield: 86%; Rf (2/1hexane/ethyl acetate): 0.30; m.p.: 107.5-110.5° C. IR (KBr): 3388, 3020,1622, 1472 cm⁻¹.

6b) 2-phenyl-1-methyl-5-nitroindole

Sodium hydride (1.1 g, 29.0 mmol) is added to 2-phenyl-5-nitro-1H-indole(Example 5b, 6.5 g, 26.0 mmol) in 100 mL of DMF. The mixture is stirredat room temperature for 1 hour. MeI (1.62 mL, 26.0 mmol) is addeddropwise and the mixture is stirred at room temperature for 1 hour. Theresulting mixture is poured into H₂O/ice and the product is filtered offand washed with H₂O. The solid is recrystallized from hexane andfiltered off. Yield: 6.5 g (99.7%); Rf (2/1 hexane/ethyl acetate): 0.60;IR (KBr): 3434, 2923, 1515, 1462 cm⁻¹; ¹H-NMR (d₆-DMSO) 8.50 (d, J=1.5Hz, 1H); 7.90 (dd, J=8.6 Hz, 1.5 Hz, 1H); 7.80-7.30 (m, 6H); 6.75 (s,1H); 3.75 (s, 3H).

Examples of Preparation of Compounds of Formula (I) According to theSynthetic Route (b):

EXAMPLE 7 Compound 5

As an alternative to the method described in Example 5, this product maybe prepared as reported below:

N-(2-phenyl-1H-indol-5-yl)acetamidine

Prepared in a manner similar to that of Example 5. Yield: 60%; Elem.anal. C₁₆H₁₅N₃; theory C:77.08 H:6.06 N:16.85; found C:77.17 H:5.89N:16.68; IR (KBr): 3434, 3024, 1634, 1597 cm⁻¹; ¹H-NMR (d₆-DMSO) 7.8-6.3(m, 9H); 1.8 (s, 3H).

7a) 2-phenyl-5-amino-1H-indole

Bromobenzene (0.157 ml, 0.0014 mol) anddichloro-bis(triphenylphosphine)palladium (II) (51.3 mg, 0.073 mmol) areadded to 2-boronic acid 1-N-BOC-5-(N′,N′-bisBOC)aminoindole (0.69 g,0.0014 mol) in THF (10 ml). The mixture is refluxed for 24 hours, 4N HCl(4 ml) are added and the resulting mixture is heated at 80° C. for 10hours. The resulting mixture is basified with 4M NaOH (pH=10) andextracted with ethyl acetate. The organic phases are combined, washedwith water, dried, filtered and concentrated. The solid obtained isrecrystallized from isopropyl ether. Rf (2/1 hexane/ethyl acetate):0.30; m.p.: 220.2-220.5° C. Elem. anal. C₁₄H₁₂N₂ theory C:80.74 H:5.81N:13.45; found C:80.55 H:5.76 N:13.35; ¹H-NMR (d₆-DMSO) 11.0 (s, 1H,exch. D₂O); 7.8 (dd, J=8.6 Hz, 1.5 Hz, 1H); 7.6-7.20 (m, 4H); 7.05 (d,J=8.6 Hz, 1H); 6.8-6.3 (m, 3H); 4.5 (bs, 2H, exch. D₂O).

7b) 2-Boronic acid 1-N-BOC-5-(N′,N′-bisBOC)aminoindole

Triisopropyl borate (0.8 ml, 0.0035 mol) is added to1-N-BOC-5-(N′,N′-bis-BOC)aminoindole (1 g, 0.0023 mol) in THF (3 ml).The mixture is cooled to −5° C. and 2M lithium diisopropylamide (1.38ml, 0.0028 mol) is added. The mixture is stirred at room temperature for3 hours and 1M HCl is added (pH=3). The resulting mixture is extractedwith ethyl acetate and the organic phase is washed with water. Theresulting solution is dried and concentrated. The solid isrecrystallized from isopropyl ether. Yield: 0.56 g (51%); ¹H-NMR(d₆-DMSO) 8.1 (s, 2H); 8.0 (d, 1H) 7.3 (d, 1H); 7.0 (dd, 1H); 6.6 (s,1H); 1.6 (s, 9H); 1.3 (s, 18H).

7c) 1-N-BOC-5-(N′,N′-bisBOC)aminoindole

DMAP (1.66 g, 0.013 mol) and di-tert-butyl dicarbonate (32.6 g, 0.149mol) are added to 5-aminoindole (9 g, 0.068 mol) in THF (300 ml). Themixture is stirred at room temperature for 48 hours, and further DMAP(0.83 g, 0.007 mol) and di-tert-butyl dicarbonate (14.8 g, 0.068 mol)are added. The resulting mixture is stirred at room temperature for afurther 6 days. This mixture is evaporated, and the solid isrecrystallized from dilute citric acid and filtered off. The solid isrecrystallized from isopropyl ether and filtered off. Yield: 2.04 g;m.p.: 189.6-192.7° C. IR (KBr): 3450, 3140, 1740, 1470, 1160, 1120, 780cm⁻¹; ¹H-NMR (d₆-DMSO) 8 (d, 1H); 7.7 (d, 1H); 7.4 (d, 1H); 7.1 (dd,1H); 6.7 (d, 1H); 1.6 (s, 9H); 1.3 (s, 18H).

EXAMPLE 8 Compound 8 N-(2-phenylquinol-6-yl)acetamidine

Prepared in a manner similar to that of Example 1. Yield: 48%; Elem.anal. C₁₇H₁₅N₃; theory C:78.13 H:5.79 N:16.08; found C:77.27 H:5.91N:15.70; IR (KBr): 3345, 3055, 1640, 1600, 1480 cm⁻¹; ¹H-NMR (d₆-DMSO)8.2-8.05 (m, 4H); 7.85 (d, 1H); 7.55-7.7 (m, 2H); 7.4-7.5 (m, 1H);7.35-7.3 (dd, 1H); 7.25 (bs, 1H); 4.5 (bs, 2H); 2.1 (bs, 3H).

8a) 2-phenyl-6-aminoquinoline

Pd/C (10%; 0.60 g) is added to 2-phenyl-6-nitroquinoline (7 g, 0.028mol) in THF (300 ml) and methanol (300 ml). The mixture is hydrogenatedat room temperature and at 1 atm. The catalyst is filtered off, thefiltrate is evaporated and the product is recrystallized from isopropylether. Yield: 5.7 g (92%); Rf (9/1 chloroform/methanol): 0.56; IR (KBr):3455, 3320, 3205, 1625, 1495 cm⁻¹.

8b) 2-phenyl-6-nitroquinoline

2-Chloro-6-nitroquinoline (10.5 g, 50.4 mmol) (Byoung S. L. et al.Heterocycles. 1998, 48.12, 65), phenylboronic acid (7.4 g, 60.4 mmol),palladium dichloride bis(triphenylphosphine) (0.70 g, 1.01 mmol) andbarium hydroxide (38.1 g, 0.121 mol) in 200 mL of anhydrous THF arestirred at 65° C. for 20 hours. The mixture is diluted with water,extracted with CH₂Cl₂ and evaporated, and the residue is chromatographedon silica gel (1/1 hexane/ethyl acetate). Yield: 7.8 g (62%); IR (KBr):3475, 3357, 1592, 1479 cm⁻¹.

Examples of Preparation of Compounds of Formula (I) According to theSynthetic Route (c):

EXAMPLE 9 Compound 9 N-(2-phenylbenzothiazol-5-yl)acetamidine

Triethylamine (6.9 ml, 0.050 mol) is added to methyl acetamidatehydrochloride (5.44 g, 0.050 mol) in acetonitrile (120 ml). The mixtureis stirred for 15 minutes at room temperature and2-phenyl-5-aminobenzothiazole (1.8 g, 8.56 mmol) is added. The resultingmixture is stirred at room temperature for 72 hours. The mixture isevaporated, the residue is taken up in ethyl acetate and washed withsodium hydroxide, and the product is extracted with 0.1M HCl. The acidicaqueous phases are combined, basified with NaOH (pH=10) and extractedwith ethyl acetate. The extracts are washed with water, dried andconcentrated. The product is recrystallized from isopropyl ether. Yield:2.0 g (23%); Elem. anal. C₁₅H₁₃N₃S; theory C:67.39 H:4.90 N:15.72; foundC:67.38 H:5.17 N:15.61; IR (KBr): 3378, 3053, 1650, 1593 cm⁻¹; ¹H-NMR(d₆-DMSO) 8.01 (m, 2H); 7.88 (d, 1H); 7.53 (m, 3H); 7.39 (s, 1H); 6.90(d, 1H); 1.91 (s, 3H).

9a) 2-phenyl-5-aminobenzothiazole

Prepared in a manner similar to that of Example 1a. Yield: 85%; Rf (8/2petroleum ether/ethyl acetate): 0.30; IR (KBr): 3439, 3316, 3199, 1621cm⁻¹.

9b) 2-phenyl-5-nitrobenzothiazole

PPA (210 g) is added to benzoic acid (12.96 g, 0.104 mol) and sodium2-amino-4-nitrothiophenoxide (19.98 g, 0.104 mol) (V. L. Guarda,Heterocyclic Comm., 2000, 1.6, 49-54). The mixture is heated at 115-120°C. for 10 minutes, cooled, and water (200 ml) is added dropwise,followed by addition of 32 percent NaOH (pH=5). The product is filteredoff and suspended in NaHCO₃ ss, filtered off, washed with water andrecrystallized from isopropyl ether. Yield: 17.0 g (64%); IR (KBr):1515, 1341 cm⁻¹; ¹H-NMR (d₆-DMSO) 8.77 (d, 1H); 8.39 (d, 1H); 8.25 (dd,1H); 8.11 (dd, 1H); 7.61 (m, 4H).

EXAMPLE 10 Compound 10N-[2-(2-methoxyphenyl)benzothiazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 9. Yield: 67%; Elem.anal. C₁₆H₁₅N₃OS; theory C:64.62 H:5.08 N:14.13; found C:64.71 H:5.04N:14.29; IR (KBr): 3439, 3067, 1641, 1586, cm⁻¹; ¹H-NMR (d₆-DMSO) 8.31(d, 1H); 7.93 (d, 1H); 7.29 (m, 4H); 6.71 (m, 1H); 6.05 (m, 2H); 3.95(s, 3H).

10a) 2-(2-methoxyphenyl)-5-aminobenzothiazole

Prepared in a manner similar to that of Example 1a. Yield: 51%; Rf(85/25/1/2 chloroform/methanol/aqueous ammonia/water): 0.84; Elem. anal.C₁₄H₁₂N₂OS; theory C:65.60 H:4.72 N:10.93; found C:65.44 H:4.61 N:10.97;IR (KBr): 3418, 3302, 3197, 1606, 1428 cm⁻¹.

10b) 2-(2-methoxyphenyl)-5-nitrobenzothiazole

Prepared in a manner similar to that of Example 9b. Yield: 59%; Rf (8/2petroleum ether/ethyl acetate): 0.54; C₁₄H₁₀N₂O₃S; M.W.: 286.30.

EXAMPLE 11 Compound 11 N-[2-benzylbenzothiazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 9. Yield: 43%; Elem.anal. C₁₆H₁₅N₃S; theory C:68.30 H:5.37 N:14.93; found C:67.90 H:5.75N:14.59; IR (KBr): 3320, 3085, 1625, 1105 cm⁻¹; ¹H-NMR (d₆-DMSO) 7.8 (m,1H); 7.3 (m, 6H); 6.8 (m, 1H); 6.0 (m, 2H); 1.9 (m, 3H).

11a) 2-benzyl-5-aminobenzothiazole

Prepared in Example 1a. Yield: 68%; Rf (95:5:0.5chloroform/methanol/aqueous ammonia): 0.46; IR (KBr): 3410, 3305, 3205,1595, 1463, 1425 cm⁻¹.

11b) 2-benzyl-5-nitrobenzothiazole

Prepared in a manner similar to that of Example 9b. Yield: 69%; Rf (8:2petroleum ether/ethyl acetate): 0.58; IR (KBr): 1525, 1335, 695 cm⁻¹.

EXAMPLE 12 Compound 12 N-[2-styrylbenzothiazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 9. Yield: 32%; Elem.anal. C₁₇H₁₅N₃S; theory C:69.60 H:5.15 N:14.32; found C:69.89 H:5.28N:14.11; IR (KBr): 3320, 3080, 1625 cm⁻¹; ¹H-NMR (d₆-DMSO) 8.0-7.1 (m,9H); 6.9 (m, 1H); 6.1 (m, 2H); 1.9 (m, 3H).

12a) 2-styryl-5-nitrobenzothiazole

Prepared in a manner similar to that of Example 1a. Yield: 69%; Rf (8/2petroleum ether/ethyl acetate): 0.54; IR (KBr): 1515, 1335, 740 cm⁻¹.

12b) 2-styryl-5-aminobenzothiazole

Prepared in a manner similar to that of Example 9b. Yield: 68%; Rf(95/5/0.5 chloroform/methanol/aqueous ammonia): 0.50; IR (KBr): 3440,3330, 1605, 1320 cm⁻¹.

EXAMPLE 13 Compound 13N-[2-(5-aminosulfonyl-2-methoxyphenyl)benzothiazol-5-yl]acetamidinehydrochloride

TEA (1.5 ml, 0.008 mol) is added to methyl acetamidate hydrochloride(0.83 g, 0.008 mol) in acetonitrile (20 ml). The mixture is stirred atroom temperature for 15 minutes, and2-(5-aminosulfonyl-2-methoxyphenyl)-5-aminobenzothiazole (1.0 g, 0.003mol) is added. The mixture is stirred at 35° C. for 96 hours andfiltered. The solid is recrystallized from 9/1 THF/methanol. Yield: 0.22g (18%); Elem. anal. C₁₆H₁₇N₄O₃S₂Cl; IR (KBr): 3034, 1678, 1143 cm⁻¹;¹H-NMR (d₆-DMSO) 8.81 (d, 1H); 8.20 (d, 1H); 7.91 (m, 2H); 7.45 (m, 6H);4.11 (s, 3H); 2.40 (m, 3H).

13a) 2-(5-aminosulfonyl-2-methoxyphenyl)-5-aminobenzothiazole

Chlorosulfonic acid (16 ml, 0.24 mol) and2-(2-methoxyphenyl)-5-nitrobenzothiazole (13.5 g, 0.047 mol) are stirredtogether at 0° C. for 15 minutes, the mixture is allowed to warm to roomtemperature and stirring is continued for one hour. The mixture ispoured into ice-water and the product is filtered off and washed withwater. The product is added portionwise to a mixture of 32% aqueousammonia (80 ml) and water (150 ml) at 0° C. This mixture is stirred for2 hours at 0° C., and is allowed to warm to room temperature, acidifiedwith HCl and filtered. The product is added to a solution of tindichloride (31.8 g, 0.151 mol) in conc. HCl (43 ml) at 0° C. Thismixture is heated at 95° C. for 60 minutes. It is cooled and brought topH=7.5 with NaOH. The resulting mixture is extracted with chloroform.The extracts are concentrated and the product obtained is recrystallizedfrom isopropyl ether/methanol. Yield: 1.3 g; ¹H-NMR (d₆-DMSO) 8.81 (d,1H); 7.87 (dd, 1H); 7.64 (d, 1H); 7.35 (m, 4H); 6.65 (dd, 2H); 4.09 (s,3H).

EXAMPLE 14 Compound 14 N-[2-(2-pyridyl)benzothiazol-5-yl]acetamidine

Prepared from 2-(2-pyridyl)-5-aminobenzothiazole in a manner similar tothat of Example 1. Yield: 2.2 g (59%); Elem. anal. C₁₄H₁₂N₄S; theoryC:62.66 H:4.51 N:20.88; found C:61.92 H:4.55 N:20.65; IR (KBr): 3390,3050, 1650, 1590 cm⁻¹; ¹H-NMR (d₆-DMSO) 8.7 (d, 1H); 8.3-7.2 (m, 5H);6.90 (m, 1H); 6.1 (m, 2H); 1.91 (m, 3H).

14a) 2-(2-pyridyl)-5-aminobenzothiazole

PPA (500 g) is added to picolinic acid (24.6 g, 0.2 mol) and sodium2-amino-4-nitrothiophenoxide (47 g, 0.2 mol). The mixture is heated at120-130° C. for 6 hours. The resulting mixture is cooled and NaOH isadded dropwise (pH=10). The product is filtered off and washed withwater. The 2-(2-pyridyl)-5-nitrobenzothiazole is recrystallized from 9/1isopropyl ether/methanol and is added to a solution of tin dichloride(61.6 g, 0.273 mol) in conc. HCl (50 ml) at 0° C. This mixture is heatedat 95° C. for 120 minutes. It is cooled and NaOH is added dropwise(pH=10). The resulting mixture is extracted with chloroform and thecombined organic phases are extracted with 0.5M HCl. The acidic aqueousphases are combined, basified with NaOH (pH=10) and extracted with ethylacetate. The extracts are washed with water and evaporated. The solidobtained is recrystallized from isopropyl ether. Yield: 3.6 g; Rf (9/1chloroform/methanol): 0.45; IR (KBr): 3400, 3325, 3215, 1590, 1430,1320, 780 cm⁻¹.

EXAMPLE 15 Compound 15N-[2-(4-methoxyphenyl)benzothiazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 9. Yield: 59%; Elem.anal. C₁₆H₁₅N₃OS; theory C:64.62 H:5.08 N:14.13; found C:64.46 H:5.10N:13.99; IR (KBr): 3435, 3330, 3200, 1640, 1245 cm⁻¹; ¹H-NMR (d₆-DMSO)8.0 (m, 3H); 7.1 (m, 4H); 6.1 (m, 2H); 3.8 (s, 3H); 1.9 (m, 3H).

15a) 2-(4-methoxyphenyl)-5-aminobenzothiazole

Iron powder (45.9 g, 0.822 mol), water (70 ml) and 37% hydrochloric acid(1.6 ml, 0.019 mol) are added to2-(4-methoxyphenyl)-5-nitrobenzothiazole (10.95 g, 0.038 mol) in ethanol(300 ml). The mixture is heated at 80° C. for one hour. The resultingmixture is filtered and evaporated, and the residue is taken up in ethylacetate and basified with NaOH (pH=11). The organic phase is filteredand washed with water. The resulting solution is evaporated and theproduct obtained is recrystallized from isopropyl ether. Yield: (61%);Rf (9/1 chloroform/methanol): 0.60; Elem. anal. C₁₄H₁₂N₂OS; theoryC:65.60 H:4.72 N:10.93; found C:65.44 H:4.87 N:10.37; IR (KBr): 3440,3320, 1600, 1465, 1245, 1170 cm⁻¹.

15b) 2-(4-methoxyphenyl)-5-nitrobenzothiazole

Prepared in a manner similar to that of Example 9b. Yield: 45%; Rf (8/2petroleum ether/ethyl acetate): 0.45; IR (KBr): 1600, 1515, 1485, 1255cm⁻¹.

EXAMPLE 16 Compound 16N-[2-(2,4-dimethoxyphenyl)benzothiazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 9. Yield: 40%; Elem.anal. C₁₇H₁₇N₃O₂S; theory C:62.36 H:5.23 N:12.83; found C:62.19 H:5.13N:12.71; IR (KBr): 3420, 3310, 1645, 1440, 1280 cm⁻¹; ¹H-NMR (d₆-DMSO)8.2 (m, 1H); 7.8 (m, 1H); 6.9 (m, 4H); 6.1 (m, 2H); 4.0 (s, 3H); 3.9 (s,3H); 1.9 (m, 3H).

16a) 2-(2,4-dimethoxyphenyl)-5-aminobenzothiazole

Prepared in a manner similar to that of Example 15a. Yield: 44%; Rf (9/1chloroform/methanol): 0.67; Elem. anal. C₁₅H₁₅N₂O₂S; theory C:62.70H:5.26 N:9.75; found C:62.87 H:4.79 N:9.16; IR (KBr): 3440, 3285, 3190,1605, 1500, 1285, 1025 cm⁻¹.

16b) 2-(2,4-dimethoxyphenyl)-5-nitrobenzothiazole

Prepared in a manner similar to that described in Example 9b. Yield:54%; Rf (6/4 toluene/ethyl acetate): 0.77; IR (KBr): 3435, 2935, 1605,1510, 1285, 816 cm⁻¹.

EXAMPLE 17 Compound 17N-[2-(3-methoxyphenyl)benzothiazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 9. Yield: 19%; Elem.anal. C₁₆H₁₅N₃OS; theory C:64.62 H:5.08 N:14.13; found C:64.49 H:5.62N:12.80; IR (KBr): 3310, 3065, 1594, 1435, 1270 cm⁻¹; ¹H-NMR (d₆-DMSO)7.9 (m, 1H); 7.3 (m, 6H); 6.1 (m, 2H); 3.8 (s, 3H); 1.9 (m, 3H).

17a) 2-(3-methoxyphenyl)-5-aminobenzothiazole

Prepared in a manner similar to that of Example 15a. Yield: 70%; Rf (9/1chloroform/methanol): 0.70; IR (KBr): 3430, 3315, 3205, 1600, 1270, 820cm⁻¹.

17b) 2-(3-methoxy-phenyl)-5-nitrobenzothiazole

Prepared in a manner similar to that described in Example 9b. Yield:22%; Rf (8/2 petroleum ether/ethyl acetate): 0.57; IR (KBr): 1673, 1515,1340, 740 cm⁻¹.

EXAMPLE 18 Compound 18N-[2-(2-methylphenyl)benzothiazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 9. Yield: 33%; Elem.anal. C₁₆H₁₅N₃S; theory C:68.30 H:5.37 N:14.93; found C:68.10 H:5.32N:1.74; IR (KBr): 3310, 3065, 1594, 1435, 1270 cm⁻¹; ¹H-NMR (d₆-DMSO)7.9 (m, 2H); 7.5 (m, 4H); 6.9 (m, 1H); 2.6 (s, 3H); 1.9 (m, 3H).

18a) 2-(2-methylphenyl)-5-aminobenzothiazole hydrochloride

Prepared in a manner similar to that of Example 15a. Yield: 65%; Rf (9/1chloroform/methanol): 0.72; IR (KBr): 2860, 2610, 1530, 1450, 755 cm⁻¹.

18b) 2-(2-methylphenyl)-5-nitrobenzothiazole

Prepared in a manner similar to that of Example 9b. Yield: 48%; Rf (8/2petroleum ether/ethyl acetate): 0.67; IR (KBr): 1678, 1515, 1340 cm⁻¹.

EXAMPLE 19 Compound 19N-[2-(4-fluorophenyl)benzimidazol-5-yl]acetamidine dihydrochloride

Prepared in a manner similar to that of Example 9. Yield: 36%; Elem.anal. C₁₅H₁₅C₁₂FN₄; theory C:52.80 H:4.43 N:16.42; found C:52.43 H:4.71N:16.01; IR (KBr): 3042, 1677, 1616, 1441, 1233 cm⁻¹; ¹H-NMR (d₆-DMSO)11.40 (s, 1H); 9.45 (s, 1H); 8.36 (m, 3H); 7.29 (m, 6H); 2.25 (m, 3H).

19a) 2-(4-fluorophenyl)-5-aminobenzimidazole dihydrochloride

Prepared in a manner similar to that of Example 4a. Yield: 74%; Rf(95/5/0.5 chloroform/methanol/aqueous ammonia): 0.33; IR (KBr): 2810,1612, 1505, cm⁻¹; ¹H-NMR (d₆-DMSO) 10.42 (m, 5H); 8.38 (m, 2H); 7.62 (m,7H).

19b) 2-(4-fluorophenyl)-5-nitrobenzimidazole

Prepared from 4-nitrophenylenediamine and 4-fluorobenzoic acid, in amanner similar to that of Example 9b. Yield: 76%; Rf (7/3 toluene/ethylacetate): 0.54; IR (KBr): 3312, 1601, 1498, 1333 cm⁻¹.

EXAMPLE 20 Compound 20N-[2-(4-chlorophenyl)benzimidazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 1. Yield: 54%;C₁₅H₁₃ClN₄; IR (KBr) 3425, 3300, 3145, 1637, 1475 cm⁻¹; ¹H-NMR (d₆-DMSO)8-8.2 (m, 3H); 7.3-7.7 (m, 4H); 6.9-6.5 (m, 2H); 1.8 (s, 3H).

20a) 2-(4-chlorophenyl)-5-aminobenzimidazole hydrochloride

Prepared in a manner similar to that of Example 4a. Yield: 94%; Rf(95/5/0.5 chloroform/methanol/aqueous ammonia): 0.22; IR (KBr): 3330,1635, 1470, 1090, 825 cm⁻¹.

20b) 2-(4-chlorophenyl)-5-nitrobenzimidazole

Prepared from 4-chlorobenzoic acid (17.83 g, 0.114 mol) and2-amino-5-nitroaniline (18 g, 0.114 mol), in a manner similar to that ofExample 9b. Yield: 87%; Rf (6/4 toluene/ethyl acetate): 0.61; m.p.:302.5-305° C.

EXAMPLE 21 Compound 21 N-(2-phenyl-3H-benzimidazol-5-yl)acetamidinehydrochloride

Prepared in a manner similar to that of Example 1. Yield: 39%; Elem.anal. C₁₅H₁₅ClN₄; theory C:62.83 H:5.27 N:19.54; found C:61.59 H:6.09N:19.02; IR (KBr): 3347, 3190, 1638, 1590, 1460 cm⁻¹; ¹H-NMR (d₆-DMSO)8.1-8.4 (m, 2H); 7.3-7.8 (m, 4H); 6.9 (d, J=1.5 Hz, 1H); 6.6 (dd, J=8.6Hz, 1.5 Hz, 1H); 1.8 (s, 3H).

21a) 2-phenyl-5-aminobenzimidazole

Prepared in a manner similar to that of Example 4a. Yield: 4.2 g (74%);Rf (9/1 chloroform/methanol): 0.20; Elem. anal. C₁₃H₁₁N₃; theory C:74.62H:5.29 N:20.08; found C:73.95 H:5.26 N:19.92.

21b) 2-phenyl-5-nitrobenzimidazole

Prepared from 4-nitrophenylenediamine and benzoic acid in a mannersimilar to that of Example 9b. Yield: 70%; Rf (9/1 chloroform/methanol):0.45; IR (KBr): 3290, 1500, 1330, 1290 cm⁻¹.

EXAMPLE 22 Compound 22 N-(2-pentyl-3H-benzimidazol-5-yl)acetamidinedihydrochloride

Prepared in a manner similar to that of Example 1. Yield: 61%; Elem.anal. C₁₄H₂₂Cl₂N₄; theory C:53.01 H:6.99 N:17.66 found C:53.20 H:7.00N:17.63; IR (KBr): 3300, 2866, 1671, 1609 cm⁻¹; ¹H-NMR (d₆-DMSO) 11.7(bs, 1H); 9.8 (bs, 1H); 8.6 (bs, 1H); 7.8 (d, J=8.6 Hz, 1H); 7.7 (d,J=1.5 Hz, 1H); 7.4 (dd, J=8.6 Hz, 1.5 Hz, 1H); 3.14 (t, 2H); 2.41 (s,3H); 1.90 (m, 2H); 1.57-1.05 (m, 4H); 0.87 (t, 3H).

22a) 2-pentyl-5-amino-3H-benzimidazole

Prepared in a manner similar to that of Example 4a. Yield: 98%.

22b) 2-pentyl-5-nitro-3H-benzimidazole

Prepared from 4-nitrophenylenediamine in a manner similar to that ofExample 4c. Yield: 78%; Rf (9/1 chloroform/methanol): 0.70; ¹H-NMR(CDCl₃) 10.2 (bs, 1H); 8.4 (d, J=1.5 Hz, 1H); 8.1 (dd, J=8.6 Hz, 1.53Hz, 1H); 7.5 (d, J=8.6 Hz, 1H); 3.0 (t, 2H); 1.90 (m, 2H); 1.6-1.1 (m,4H); 0.87 (t, 3H).

EXAMPLE 23 Compound 23N-[2-(pyrrol-2-yl)-3H-benzimidazol-5-yl]acetamidine dihydrochloride

1N NaOH (pH=10) is added toN-[2-(pyrrol-2-yl)-3H-benzimidazol-5-yl]acetamidine hydrobromide(Example 24) (2.2 g, 0.007 mol) in water (30 ml). The precipitate isfiltered off and recrystallized from isopropyl ether. The solid is takenup in methanol and the dihydrochloride is precipitated from isopropylether/HCl. Yield: 1.7 g (79%); Elem. anal. C₁₃H₁₅Cl₂N₅; theory C:50.01H:4.84 N:22.43; found C:50.05 H:4.79 N:22.17; IR (KBr): 3044, 1674, 1620cm⁻¹.

EXAMPLE 24 Compound 24N-[2-(pyrrol-2-yl)-3H-benzimidazol-5-yl]acetamidine hydrobromide

2-Naphthylmethyl thioacetamidate hydrobromide (3.3 g, 0.011 mol) isadded, at room temperature and with stirring, to2-(pyrrol-2-yl)-5-amino-1H-benzimidazole (2.2 g, 0.011 mol) in ethanol(30 ml). The mixture is stirred for 18 hours at room temperature andfiltered, and the solid is recrystallized from isopropyl ether. Yield:3.0 g (85%); C₁₃H₁₃N₅.HBr; m.p.: 197-199° C.; IR (KBr): 3053, 1675,1629, 1601, 1508 cm⁻¹; ¹H-NMR (d₆-DMSO) 11.6 (s, 1H); 11.1 (s, 1H); 9.3(s, 1H); 8.4 (s, 1H); 7.5 (d, 1H); 7.4 (d, 1H); 7.0 (m, 2H); 6.2 (m,2H); 2.4 (s, 3H).

24a) 2-(pyrrol-2-yl)-5-amino-1H-benzimidazole

Prepared in a manner similar to that of Example 4a. Yield: 38%; Rf(85/25/2/1 chloroform/methanol/water/aqueous ammonia): 0.67; IR (KBr):3367, 1630 cm⁻¹; ¹H-NMR (d₆-DMSO) 11.5 (m, 1H); 7.2 (d, 1H); 6.6-6.9 (m,3H); 6.5 (dd, 2H); 6.1 (m, 1H).

24b) 2-(pyrrol-2-yl)-5-nitro-1H-benzimidazole

Pyrrolyl-2-carboxaldehyde (10.6 g, 0.104 mol) is added to2-amino-4-nitroaniline (14 g, 0.090 mol) in DMF (400 ml), and themixture is heated at 110° C. for 60 hours, cooled and concentrated. Thesolid is recrystallized from water and then from isopropyl ether. Yield:15.5 g (71%); IR (KBr): 3100, 1596, 1506, 1327 cm⁻¹; ¹H-NMR (d₆-DMSO)8.2 (m, 1H); 8.0 (m, 1H); 7.5-7.7 (m, 1H); 6.9 (m, 3H); 6.2 (m, 2H).

EXAMPLE 25 Compound 25 Methyl4-(5-acetimidoylamino-1H-benzimidazol-2-yl)benzoate hydrochloride

Prepared in a manner similar to that of Example 1. Yield: 27%; IR (KBr):3447, 3050, 1717, 1610, 1277 cm⁻¹; ¹H-NMR (d₆-DMSO) 11.61 (s, 1H); 9.54(s, 1H); 8.53 (d, 2H); 8.12 (d, 2H); 7.78 (m, 3H); 7.25 (dd, 2H); 6.64(m, 3H); 3.81 (s, 3H); 2.34 (s, 3H).

25a) Methyl 4-(5-amino-1H-benzimidazol-2-yl)benzoate

Prepared in a manner similar to that of Example 4a. Yield: 57%; Rf (9/1chloroform/methanol): 0.33; Elem. anal. C₁₅H₁₃N₃O₂; theory C:67.40H:4.90 N:15.72; found C:66.24 H:4.89 N:14.54; IR (KBr): 3311, 1689,1611, 1282, 1111 cm⁻¹.

25b) Methyl 4-(5-nitro-1H-benzimidazol-2-yl)benzo-ate

Sodium bisulfite (7.0 g, 0.036 mol) in water (70 ml) is added to4-carboxybenzaldehyde (11.0 g, 0.071 mol) in ethanol (70 ml). Themixture is stirred at room temperature for 15 minutes, the solid isfiltered off, the filtrate is coevaporated with toluene and a solutionof 2-amino-5-nitroaniline (11.1 g, 0.071 mol) in DMF (250 ml) is added.This mixture is refluxed for 3 hours and concentrated, and the productis recrystallized from dilute HCl, filtered off and washed with water.The solid is suspended in methanol (300 ml) and HCl gas is bubbledthrough at 5-15° C. for 3 hours. The mixture is allowed to warm to roomtemperature and is then refluxed for 3 hours. The solution isconcentrated to ⅓ of its volume and cooled to +5° C., and theprecipitate is filtered off and recrystallized from NaHCO₃ and finallyfrom 3/1 isopropyl ether/hexane. Yield: 15 g (71%); IR (KBr): 3570,3472, 3112, 1707, 1301 cm⁻¹; ¹H-NMR (d₆-DMSO) 7.7-8.5 (m, 7H); 5.9 (m,1H); 3.88 (s, 3H).

EXAMPLE 26 Compound 264-(5-acetimidoylamino-1H-benzimidazol-2-yl)benzoic acid

Prepared in a manner similar to that of Example 1. Yield: 67%; Elem.anal. C₁₆H₁₄N₄O₂; theory C:65.30 H:4.79 N:19.04; found C:63.31 H:5.37N:17.19; IR (KBr): 3220, 1590, 1544, 1378 cm⁻¹.

26a) 4-(5-amino-1H-benzimidazol-2-yl)benzoic acid

Prepared in a manner similar to that of Example 4a. Yield: 83%; Rf(4/4/2 chloroform/methanol/aqueous ammonia): 0.70; IR (KBr): 3117, 1604,1540, 1397 cm⁻¹.

26b) 4-(5-nitro-1H-benzimidazol-2-yl)benzoic acid

2M NaOH (75 ml) is added, at 0° C., to methyl4-(5-nitro-1H-benzimidazol-2-yl)benzoate (15 g, 0.050 mol) (Example 26)in methanol (250 ml). The mixture is stirred at room temperature for 20hours and evaporated, and the residue is taken up in water and acidifiedwith HCl (pH=6). The resulting mixture is stirred for 16 hours at 0° C.,and the product is filtered off, washed with water and recrystallizedfrom 9/1 methanol/isopropyl ether. Yield: 10 g (70%); IR (KBr): 3357,1675, 1602, 1537, 1377, 1320 cm⁻¹; ¹H-NMR (d₆-DMSO) 7.5-8.6 (m, 7H).

EXAMPLE 27 Compound 27 N-(2-phenylquinazolin-6-yl)acetamidinedihydrochloride

Isopropyl ether/HCl is added to 2-phenyl-6-(N-acetamidino)quinazoline(0.9 mg, 0.0034 mol) in methanol (5 ml) at 0° C. The product is filteredoff and recrystallized from isopropyl ether/isopropyl alcohol. Yield:0.8 g (20%); Elem. anal. C₁₆H₁₆Cl₂N₄; theory C:57.32 H:4.81 N:16.71;found C:56.38 H:6.05 N:15.29; IR (KBr): 3453, 3095, 1658, 1600, 1553,1343 cm⁻¹; ¹H-NMR (d₆-DMSO) 11.81 (s, 1H); 9.74 (s, 2H); 8.83 (m, 1H);8.48 (m, 2H); 8.12 (m, 2H); 7.83 (d, 1H); 7.34 (m, 4H); 2.34 (s, 3H).

27b) N-(2-phenylquinazolin-6-yl)acetamidine

Prepared in a manner similar to that of Example 9. Yield: 20%; m.p.:162-164° C. Elem. anal. C₁₅H₁₃N₃S; theory C:73.26 H:5.38 N:21.36; foundC:72.65 H:5.46 N:21.09; IR (KBr): 3453, 3095, 1658, 1600, 1553, 1343cm⁻¹; ¹H-NMR (d₆-DMSO) 9.41 (s, 1H); 8.48 (m, 2H); 7.83 (d, 1H); 7.34(m, 6H); 6.30 (m, 1H); 1.85 (s, 3H).

27c) 2-phenyl-6-aminoquinazoline

Prepared in a manner similar to that of Example 4a. Yield: 74%; Elem.anal. C₁₄H₁₁N₃; theory C:76.00 H:5.01 N:18.99; found C:75.85 H:5.12N:18.58; IR (KBr): 3455, 3315, 1622, 1494, 1385, 1242 cm⁻¹; ¹H-NMR(d₆-DMSO) 9.21 (s, 1H); 8.45 (m, 1H); 7.50 (m, 5H); 6.85 (d, 1H); 5.88(s, 2H).

27d) 2-phenyl-6-nitroquinazoline

2-Phenyl-6-nitro-3,4-dihydroquinazoline (27 g, 0.106 mol) and chloranil(32.4 g, 0.13 mol) in toluene (450 ml) are refluxed for 60 minutes. Themixture is cooled to room temperature, and the precipitate is filteredoff and washed with toluene (350 ml). The filtrate is suspended in 0.5NNaOH (400 ml) and the aqueous phase is extracted with dichloromethane(100 ml). The combined organic phases are washed with water andconcentrated. The solid is recrystallized from hexane. Yield: 8.8 g(34%); Rf (8/2 petroleum ether/ethyl acetate): 0.71; ¹H-NMR (d₆-DMSO)9.91 (s, 1H); 9.18 (d, 1H); 8.61 (m, 3H); 8.24 (d, 1H); 7.55 (m, 3H).

27e) 2-phenyl-6-nitro-3,4-dihydroquinazoline

N-Benzoyl-2-amino-5-nitrobenzylamine (33 g, 0.12 mol) and phosphorylchloride (150 ml) are refluxed for 3 hours. The mixture is concentratedand water is added, followed by addition of aqueous ammonia (pH>10). Theproduct is filtered off and recrystallized from water, and then from 2/1isopropyl ether/hexane. Yield: 27.6 g (89%); IR (KBr): 3387, 3198, 1599,1512, 1341 cm⁻¹; ¹H-NMR (d₆-DMSO) 7.95 (m, 4H); 7.30 (m, 4H); 7.01 (m,1H); 4.71 (s, 2H).

27f) N-benzoyl-2-amino-5-nitrobenzylamine

Triethylamine (116 ml, 0.835 mol) and DMAP (2.0 g, 0.016 mol) are addedto 2-amino-5-nitrobenzonitrile (68 g, 0.33 mol) in dichloromethane (1litre). The mixture is cooled to +5° C., and benzoyl chloride (38.8 ml,0.33 mol) in dichloromethane (50 ml) is added. The resulting mixture isstirred for 2 hours and then concentrated. The residue is taken up in10/1 water/ethanol (550 ml) and the product is filtered off andrecrystallized from isopropyl ether. Yield: 88.5 g (97%); IR (KBr):3375, 3213, 1638, 1547, 1319 cm⁻¹; ¹H-NMR (d₆-DMSO) 8.15 (m, 1H); 7.85(m, 4H); 7.51 (m, 4H); 6.68 (m, 3H); 4.30 (m, 2H).

27g) 2-amino-5-nitrobenzylamine hydrochloride

Borane in THF (400 ml, 0.40 mol) is added dropwise to2-amino-5-nitrobenzonitrile (60 g, 0.35 mol) in THF (600 ml) at 0° C.The mixture is allowed to warm to room temperature and is stirred for 16hours. The resulting mixture is cooled to 0° C. and 200 ml of absoluteethanol/HCl are added. The THF is removed and the product is filteredoff and recrystallized from isopropyl ether. Yield: 68.8 g (96%); Rf(1:1 methanol/chloroform): 0.15; IR (KBr): 3416, 2980, 1669, 1601, 1474,1285 cm⁻¹.

EXAMPLE 28 Compound 28 N-(2-phenylbenzofuran-5-yl)acetamidine

2-naphthylmethyl thioacetamidate hydrobromide (13.03 g, 0.044 mol) isadded to 2-phenyl-5-aminobenzofuran (9.31 g, 0.044 mol) in ethanol (200ml). The mixture is stirred at room temperature for 18 hours and is thenevaporated, NaOH (pH=10) is added and the resulting mixture is extractedwith ethyl acetate. The organic phase is extracted with 0.5M HCl. Theacidic aqueous phases are combined, basified with NaOH (pH=10) andextracted with ethyl acetate. The extracts are washed with water. Theresulting solution is evaporated and the solid obtained isrecrystallized from isopropyl ether. Yield: 7.45 g (68%); Elem. anal.C₁₆H₁₄N₂O; theory C:76.78 H:5.64 N:11.19; found C:76.18 H:5.56 N:11.02;IR (KBr): 3445, 3045, 1640, 1605, 1450, 755 cm⁻¹; ¹H-NMR (d_(6—)DMSO)7.6-8.0 (m, 2H); 7.1-7.6 (m, 6H); 6.9-6.6 (m, 1H); 5.9 (m, 2H); 1.9 (m,3H).

28a) 2-phenyl-5-aminobenzofuran

Triethylamine (63.4 ml, 0.455 mol) is added to2-hydroxy-5-nitrobenzylphsophonium bromide (50 g, 0.101 mol) inrefluxing toluene (600 ml), followed by addition of benzoyl chloride(16.2 ml, 0.140 mol) in toluene (50 ml). The mixture is refluxed for 3hours, cooled and stirred at room temperature for 2 hours. The resultingmixture is concentrated and the product is recrystallized from 2/1isopropyl ether/hexane, and the 2-phenyl-5-nitrobenzofuran is filteredoff. This product is hydrogenated in THF (300 ml) and methanol (150 ml),with Pd/C (10%; 3.2 g). The catalyst is filtered off and the filtrate isconcentrated. The residue is taken up in isopropanol/MeOH/HCl, and thehydrochloride is precipitated. It is suspended in 1M NaOH and extractedwith ethyl acetate. The extracts are washed with water and concentrated.The solid is recrystallized from isopropyl ether. Yield: 9.8 g (32%);Elem. anal. C₁₄H₁₁NO; theory C:80.36 H:5.30 N:6.70; found C:79.78 H:5.16N:6.87; IR (KBr): 3400, 3325, 1595, 1465 cm⁻¹.

EXAMPLE 29 Compound 29 N-(2-phenylbenzoxazol-5-yl)acetamidine

Prepared in a manner similar to that of Example 9. Yield: 29%; Elem.anal. C₁₅H₁₃N₃O; theory C:71.70 H:5.21 N:16.72; found C:71.48 H:4.64N:16.71; IR (KBr): 3360, 3140, 1655, 1180, 700 cm⁻¹; ¹H-NMR (d₆-DMSO)8-8.2 (m, 2H); 7.4-7.8 (m, 5H); 6.9 (dd, 1H); 5.9-6.3 (broad s, 2H); 1.8(m, 3H).

29a) 2-phenyl-5-aminobenzoxazole

Prepared in a manner similar to that of Example 4b. Yield: 83%; Rf (9/1chloroform/methanol): 0.52; m.p.: 155.3-156.7° C. Elem. anal. C₁₃H₁₀N₂O;theory C:74.27 H:4.79 N:13.32; found C:73.48 H:4.85 N:13.12; IR (KBr):3435, 3320, 1545, 1480, 1180, 695 cm⁻¹.

29b) 2-phenyl-5-nitrobenzoxazole

Prepared from 2-amino-4-nitrophenol and benzoic acid, in a mannersimilar to that of Example 9b. Yield: 85%; Rf (9/1 chloroform/methanol):0.92; Elem. anal. C₁₃H₈N₂O₃; theory C:65.00 H:3.35 N:11.66; foundC:64.54 H:3.35 N:11.85; IR (KBr): 1615, 1530, 1345 cm⁻¹.

EXAMPLE 30 Compound 30 N-[2-(4-chlorophenyl)benzoxazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 28. Yield: 29%; Rf(5/2/2 butanol/acetic acid/water): 0.58; Elem. anal. C₁₅H₁₂ClN₃O; theoryC:62.77 H:4.25 N:14.77; found C:63.05 H:4.23 N:14.70; m.p.: 183.6-185.1°C. IR (KBr): 3455, 3295, 3145, 1645, 1400, 835 cm⁻¹; ¹H-NMR (d₆-DMSO)8.1 (m, 2H); 7.6 (m, 3H); 7.1 (m, 1H); 6.9 (m, 1H); 1.9 (broad s, 3H).

30a) 2-(4-chlorophenyl)-5-aminobenzoxazole

Prepared in a manner similar to that of Example 1a. Yield: 44%; IR(KBr): 3430, 3340, 1625, 1595, 1475, 830 cm⁻¹.

30b) 2-(4-chlorophenyl)-5-nitrobenzoxazole

Prepared in a manner similar to that of Example 9b. Yield: 28%; Rf (7/3toluene/chloroform): 0.58; IR (KBr): 3095, 1605, 1525, 1335, 820 cm⁻¹.

EXAMPLE 31 Compound 31N-[2-(3-trifluromethylphenyl)benzoxazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 28. Yield: 56%; Elem.anal. C₁₆H₁₂F₃N₃O; theory C:60.19 H:3.79 N:13.16; found C:60.44 H:4.22N:13.05; m.p.: 157.9-159.2° C. IR (KBr): 3330, 3105, 1660, 1615, 1280,1175 cm⁻¹; ¹H-NMR (d₆-DMSO) 8.4 (m, 2H); 7.8 (m, 3H); 7.1 (m, 2H); 6.1(m, 2H); 1.9 (m, 3H).

31a) 2-(3-trifluromethylphenyl)-5-aminobenzoxazole

Prepared in a manner similar to that of Example 4a. Yield: 80%; Rf (9/1chloroform/methanol): 0.59; IR (KBr): 3435, 3335, 1620, 1340, 1120 cm⁻¹.

31b) 2-(3-trifluromethylphenyl)-5-nitrobenzoxazole

3-Trifluoromethylbenzoyl chloride (9.03 g, 0.043 mol) and2-hydroxy-5-nitroaniline (6.58 g, 0.041 mol) in toluene (200 ml) arerefluxed for 48 hours. POCl₃ (20 ml) is added, the mixture is refluxedfor a further 2 hours and concentrated, and the solid is recrystallizedfrom NaOH (pH=10). The product is filtered off and recrystallized fromwater and finally from isopropyl ether. Yield: 10.3 g (78%); Rf (8/2petroleum ether/ethyl acetate): 0.58; IR (KBr): 3085, 1620, 1531, 1425,1340 cm⁻¹.

EXAMPLE 32 Compound 32N-[2-(4-trifluromethylphenyl)benzoxazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 28. Yield: 56%;C₁₆H₁₂F₃N₃O; IR (KBr): 3455, 3100, 1645, 1610, 1465, 1325, 1115 cm⁻¹.

32a) 2-(4-trifluromethylphenyl)-5-aminobenzoxazole

Prepared in a manner similar to that of Example 4a. Yield: 71%; Rf (9/1chloroform/methanol): 0.50; IR (KBr): 3440, 3355, 1620, 1330, 1105 cm⁻¹.

32b) 2-(4-trifluromethylphenyl)-5-nitrobenzoxazole

Prepared in a manner similar to that of Example 31b. Yield: 57%; Rf (8/2hexane/ethyl acetate): 0.66; IR (KBr): 3105, 1610, 1530, 1345, 1115cm⁻¹.

EXAMPLE 33 Compound 33 N-[2-(2-fluorophenyl)benzoxazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 28. Yield: 65%;C₁₅H₁₂FN₃O; IR (KBr): 3340, 3110, 1655, 1605, 1460, 1395 cm⁻¹; ¹H-NMR(d₆-DMSO) 8.4 (m, 2H); 7.8 (m, 3H); 7.1 (m, 2H); 6.1 (m, 2H); 1.9 (m,3H).

33a) 2-(2-fluorophenyl)-5-aminobenzoxazole

Prepared in a manner similar to that of Example 4a. Yield: 76%; Rf (9/1chloroform/methanol): 0.61; IR (KBr): 3430, 3325, 1585, 1480, 1445 cm⁻¹.

33b) 2-(2-fluorophenyl)-5-nitrobenzoxazole

Prepared in a manner similar to that of Example 31b. Yield: 33%; Rf (8/2hexane/ethyl acetate): 0.48; IR (KBr): 3095, 1615, 1525, 1485, 1340cm⁻¹.

EXAMPLE 34 Compound 34N-[2-(3,4-dichlorophenyl)benzoxazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 28. Yield: 75%; Elem.anal. C₁₅H₁₁Cl₂N₃O; theory C:56.27 H:3.46; N:13.12; found C:56.01 H:3.58N:13.22; IR (KBr): 3449, 3084, 1644, 1460 cm⁻¹; ¹H-NMR (d₆-DMSO) 8.3 (d,2H); 8.1 (dd, 1H); 7.5-7.9 (m, 4H); 7.1 (m, 1H); 6.9 (m, 1H); 1.9 (m,3H).

34a) 2-(3,4-dichlorophenyl)-5-aminobenzoxazole

Prepared in a manner similar to that of Example 1a. Yield: 55%; Rf (7/3toluene/ethyl acetate): 0.37; Elem. anal. C₁₃H₈Cl₂N₂O; theory C:55.94H:2.89 N:10.04; found C:55.55 H:3.08 N:9.82; IR (KBr): 3400, 3324, 3211,1626, 1457 cm⁻¹.

34b) 2-(3,4-dichlorophenyl)-5-nitrobenzoxazole

3,4-Dichlorobenzoyl chloride (4.6 g, 0.022 mol) is added to2-amino-4-nitrophenol (3.4 g, 0.022 mol) in toluene (250 ml) and themixture is refluxed for 24 hours. para-Toluenesulfonic acid (1.0 g) isadded, the mixture is refluxed for 24 hours and cooled, and the productis filtered off. It is recrystallized from isopropyl ether. Yield: 6.8g; IR (KBr): 3100, 1531, 1350 cm⁻¹.

EXAMPLE 35 Compound 35N-[2-(3,4-dichlorophenyl)benzimidazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 28. Yield: 37%; Elem.anal. C₁₅H₁₂Cl₂N₄; theory C:56.44 H:3.79 N:17.55; found C:55.84 H:4.58N:16.59; IR (KBr): 3375, 3300, 3170, 1630, 1450, 1395 cm⁻¹; ¹H-NMR(d₆-DMSO) 8.3 (d, 1H); 8.1 (dd, 1H); 7.7 (m, 1H); 7.4 (m, 1H); 6.9 (m,1H); 6.7 (dd, 1H); 1.9 (broad s, 3H).

35a) 2-(3,4-dichlorophenyl)-5-aminobenzimidazole

Prepared in a manner similar to that of Example 1a. Yield: 44%; Rf(95/5/0.5 chloroform/methanol/aqueous ammonia): 0.16; IR (KBr): 1630,1425, 1130 cm⁻¹.

35b) 2-(3,4-dichlorophenyl)-5-nitrobenzimidazole

Prepared from 4-nitro-2-aminophenol and 3,4-dichlorobenzoic acid, in amanner similar to that of Example 9b. Yield: 28%; Rf (7/3 toluene/ethylacetate): 0.53; IR (KBr): 3290, 1495, 1440, 1335 cm⁻¹.

EXAMPLE 36 Compound 36N-[2-(3-trifluoromethylphenyl)benzimidazole-5-yl]acetamidinehydrobromide

Prepared in a manner similar to that of Example 24. Yield: 51%; Elem.anal. C₁₆H₁₄BrF₃N₄; theory C:48.14 H:3.53; N:14.03; found C:48.04 H:3.85N:13.82; IR (KBr): 3040, 1680, 1620, 1410, 1320 cm⁻¹; ¹H-NMR (d₆-DMSO)8.5 (m, 2H); 7.7 (m, 4H); 7.1 (m, 1H); 2.4 (broad s, 3H).

36a) 2-(3-trifluoromethylphenyl)-5-aminobenzimidazole

Prepared in a manner similar to that of Example 4a. Yield: 80%; Rf (9/1chloroform/methanol): 0.25.

36b) 2-(3-trifluoromethylphenyl)-5-nitrobenzimidazole

Prepared in a manner similar to that of Example 31b. Yield: 41%; Rf (8/2toluene/ethyl acetate): 0.47; IR (KBr): 3105, 1515, 1325, 1170, 1120cm⁻¹.

EXAMPLE 37 Compound 37 2-[(2-methoxyphenyl)benzimidazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 1. Yield: 18%; Elem.anal. C₁₆H₁₆N₄O; theory C:68.55 H:5.75 N:19.99; found C:67.79 H:5.65N:19.60; IR (KBr): 3440, 3135, 1640, 1460, 1245 cm⁻¹; ¹H-NMR (d₆-DMSO)8.2 (m, 1H); 7.2 (m, 5H); 6.6 (m, 1H); 3.9 (m, 3H); 1.8 (s, 3H).

37a) 2-(2-methoxyphenyl)-5-aminobenzimidazole dihydrochloride

Prepared in a manner similar to that of Example 4a. Yield: 93%; Rf (9/1chloroform/methanol): 0.45; IR (KBr): 2835, 2610, 1635, 1495, 1455 cm⁻¹.

37b) 2-(2-methoxyphenyl)-5-nitrobenzimidazole

Prepared from 4-nitrophenylenediamine and 2-methoxybenzoic acid, in amanner similar to that of Example 9b. Yield: 76%; Rf (6/4 toluene/ethylacetate): 0.43; IR (KBr): 3005, 1515, 1335, 750 cm⁻¹.

EXAMPLE 38 Compound 38N-[2-(2-fluorophenyl)benzimidazol-5-yl]acetamidine hydrobromide

Prepared in a manner similar to that of Example 24. Yield: 82%; Elem.Anal. C₁₅H₁₄FN₄.HBr; theory C:51.59 H:4.04 N:16.04; found C:50.79 H:4.30N:15.45; IR (KBr): 3237, 2885, 1684, 1611 cm⁻¹.

38a) 2-(2-fluorophenyl)-5-aminobenzimidazole

Prepared in a manner similar to that of Example 4a. Yield: 100%; Rf (9/1chloroform/methanol): 0.25.

38b) 2-(2-fluorophenyl)-5-nitrobenzimidazole

Prepared from 4-nitrophenylenediamine and 2-fluorobenzoic acid, in amanner similar to that of Example 31b. Yield: 15%; Rf (7/3 toluene/ethylacetate): 0.55; IR (KBr): 2996, 1625, 1520, 1479, 1340 cm⁻¹; ¹H-NMR(d₆-DMSO) 8.5-8.0 (m, 3H); 7.2-7.9 (m, 4H).

EXAMPLE 39 Compound 39N-[2-(2-methylphenyl)benzimidazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 28. Yield: 38%; Elem.anal. C₁₆H₁₆N₄; theory C:72.70 H:6.10; N:21.20; found C:71.00 H:6.45N:20.35; IR (KBr): 3454, 3055, 1643, 1393 cm⁻¹; ¹H-NMR (d₆-DMSO) 7.7 (m,1H); 7.5 (m, 7H); 6.9 (m, 1H); 6.7 (dd, 1H); 2.6 (s, 3H); 1.9 (s, 3H).

39a) 2-(2-methylphenyl)-5-aminobenzimidazole

Prepared in a manner similar to that of Example 4a. Yield: 100%; Rf (9/1chloroform/methanol): 0.31; IR (KBr): 2966, 1630, 1447 cm⁻¹; ¹H-NMR(d₆-DMSO) 8.6 (m, 1H); 7.2 (m, 6H); 6.4-6.7 (m, 3H).

39b) 2-(2-methylphenyl)-5-nitrobenzimidazole

2-Methylbenzoyl chloride (4.1 g, 0.027 mol) is added to2-amino-4-nitroaniline (4 g, 0.025 mol) in toluene (100 ml), and themixture is refluxed for 24 hours. para-Toluenesulfonic acid (1.0 g) isadded, the mixture is refluxed for 36 hours and concentrated, and theresidue is taken up in ethyl acetate. The solution is washed with NaHCO₃and then with water. The resulting solution is dried and concentrated,and the solid obtained is recrystallized from isopropyl ether. Yield:3.1 g (48%); Rf (7/3 toluene/ethyl acetate): 0.58; ¹H-NMR (d₆-DMSO): 8.5(d, 1H); 8.1 (dd, 1H); 7.7 (m, 2H); 7.4 (m, 3H); 2.6 (s, 3H).

EXAMPLE 40 Compound 40 N-[2-(pyrrol-2-yl)benzothiazol-5-yl]acetamidine

Prepared in a manner similar to that of Example 1. Yield: 28%; Elem.anal. C₁₃H₁₂N₄S; theory C:60.91 H:4.72 N:21.85; found C:61.20 H:5.41N:20.07; IR (KBr): 3455, 3165, 1655, 1570, 1485 cm⁻¹; ¹H-NMR (d₆-DMSO)11.5 (broad s, 1H); 7.8 (m, 1H); 7.2-6.6 (m, 4H); 6.3-5.8 (m, 3H), 1.8(m, 3H).

40a) 2-(2-pyrrolyl)-5-aminobenzothiazole

Prepared in a manner similar to that of Example 4a. Yield: 30%; Rf (9/1chloroform/methanol): 0.44; IR (KBr): 3455, 3360, 3125, 1570, 1460 cm⁻¹.

40b) 2-(2-pyrrolyl)-5-nitrobenzothiazole

Prepared from sodium 2-amino-4-nitrothiophenoxide (15 g, 0.078 mol) andpyrrol-2-ylcarboxaldehyde (5.23 g, 0.055 mol) in a manner similar tothat of Example 24b. Yield: 3.9 g (29%); Rf (8/2 petroleum ether/ethylacetate): 0.54; IR (KBr): 1595, 1510, 1480, 1335 cm⁻¹.

EXAMPLE 41 Compound 41N-[2-phenylbenzothiazol-5-yl]cyclopropylcarboxamidine

Prepared from 2-phenyl-5-aminobenzothiazole (example 9a) and methylcyclopropylcarboximidate (Patai, The Chemistry of Functional Groups; TheChemistry of Cyano group; pp. 264-266, Zvi Rappoport, Wiley & Sons,1970) in a manner similar to that described in Example 9. Yield: 57%;Elem. anal. C₁₇H₁₅N₃O; theory C:73.63 H:5.45 N:15.15; found C:72.06H:5.29 N:14.69; IR (KBr): 3401, 1646, 1604, 1469 cm⁻¹.

EXAMPLE 42 Compound 42 N-(2-phenylbenzoxazol-6-yl)acetamidine

Prepared in a manner similar to that of Example 9. Yield: 41%; Elem.anal. C₁₅H₁₃N₃O; theory C:71.70 H:5.21 N:16.72; found C:71.06 H:4.91N:16.62; IR (KBr): 3360, 3105, 1655, 1606 cm⁻¹; ¹H-NMR (d₆-DMSO) 8-8.2(m, 2H); 7.4-7.8 (m, 5H); 6.9 (dd, 1H); 5.9-6.3 (broad s, 2H); 1.8(broad s, 3H).

42a) 2-phenyl-6-aminobenzoxazole

Prepared in a manner similar to that of Example 4a. Yield: 74%; Rf (9/1chloroform/methanol): 0.64; m.p.: 212-214° C. IR (KBr): 3400, 3305,3205, 1630 cm⁻¹

42b) 2-phenyl-6-nitrobenzoxazole

PPA (160 g) is added to benzoic acid (14.26 g, 0.117 mol) and2-amino-5-nitrophenol (20 g, 0.117 mol). The mixture is heated at115-120° C. for 30 minutes and cooled, and water (200 ml) is addeddropwise, followed by addition of 32% NaOH (pH=10). The product isfiltered off, washed with water and filtered off. It is recrystallizedfrom isopropyl ether. Yield: g (90%); Elem. anal. C₁₃H₈N₂O₃; theoryC:65.00 H:3.35 N:11.66; found C:64.56 H:3.22 N:11.43; IR (KBr): 1551,1515, 1340 cm⁻¹.

EXAMPLE 43 Compound 43N-[1-methyl-2-(2-methoxyphenyl)benzimidazol-5-yl]acetamidinedihydrochloride

Prepared in a manner similar to that of Example 28. Yield: 78%; Elem.anal. C₁₇H₂₀Cl₂N₄O; theory C:55.59 H:5.49 N:15.25; found C:54.36 H:6.05N:14.86; IR (KBr): 3450, 3020, 1605, 1490, 1260 cm⁻¹; ¹H-NMR (d₆-DMSO)12.04 (broad s, 1H); 9.78 (broad s, 1H); 8.65 (broad s, 1H); 8.12 (d,1H); 7.85 (s, 1H); 7.77 (dt, 1H); 7.71 (dd, 1H); 7.52 (dd, 1H); 7.39 (d,1H); 7.27 (t, 1H); 3.90 (s, 3H); 3.86 (s, 3H); 2.43 (s, 3H).

43a) 1-methyl-2-(2-methoxyphenyl)-5-aminobenzimidazole and1-methyl-2-(2-methoxyphenyl)-6-aminobenzimidazole

Prepared in a manner similar to that of Example 4a. The amines of thetwo isomers are separated by flash chromatography on a column of silicagel (ethyl acetate).

1-methyl-2-(2-methoxyphenyl)-6-aminobenzimidazole

Yield: 2.21 g; Rf (95/5/0.5 chloroform/methanol/aqueous ammonia): 0.33;Elem. anal. C₁₅H₁₅N₃O; theory C:71.12 H:5.97 N:16.59; found C:69.71H:6.10 N:15.29; IR (KBr): 3230, 3200, 2935, 1625, 1460, 1245 cm⁻¹;¹H-NMR (d₆-DMSO) 7.3 (m, 5H); 6.6 (m, 2H); 3.8 (s, 3H), 3.4 (s, 3H).

1-methyl-2-(2-methoxyphenyl)-5-aminobenzimidazole

Yield: 4.0 g; Rf (95/5/0.5 chloroform/methanol/aqueous ammonia): 0.25;Elem. anal. C₁₅H₁₅N₃O; theory C:71.12 H:5.97 N:16.59; found C:69.69H:6.53 N:15.03; IR (KBr): 3230, 3200, 2935, 1625, 1460, 1245 cm⁻¹;¹H-NMR (d₆-DMSO) 7.5 (m, 2H); 7.1 (m, 3H); 6.7 (m, 2H); 3.8 (s, 3H); 3.4(s, 3H).

43b) 1-methyl-2-(2-methoxyphenyl)-5-nitrobenzimidazole and1-methyl-2-(2-methoxyphenyl)-6-nitrobenzimidazole

Sodium hydride (22 g, 0.055 mol) and methyl iodide (3.15 ml, 0.050 mol)are added to 2-(2-methoxyphenyl)-5-nitrobenzimidazole (Example 37b,12.38 g, 0.046 mol) in DMF (120 ml) at 0-5° C. The mixture is stirred atroom temperature for 5 days. Water (300 ml) is added and the solid isfiltered off and recrystallized from water, and then from 9/1 isopropylether/acetonitrile, to give a mixture of the two isomers in a ratio ofabout 65:35 respectively. Yield: 9.3 g (72%); Rf (9/1 toluene-methanol):0.41 (isomer-6) and 0.36 (isomer 5); Elem. anal. C₁₅H₁₃N₃O₃; theoryC:63.59 H:4.62 N:14.83; found C:63.34 H:4.50 N:14.70.

EXAMPLE 44 Compound 44N-[1-methyl-2-(2-methoxyphenyl)benzimidazol-6-yl]acetamidine

Prepared in a manner similar to that of Example 28 from1-methyl-2-(2-methoxyphenyl)-6-aminobenzimidazole, Example 43a.

Yield: 87%; Elem. anal. C₁₇H₁₈N₄O; theory C:69.37 H:6.16 N:19.03; foundC:67.95 H:6.02 N:18.38; IR (KBr): 3450, 3350, 1650, 1605, 1470, 1255cm⁻¹; ¹H-NMR (d₆-DMSO) 7.54 (dt, 1H); 7.49 (d, 1H); 7.45 (dd, 1H); 7.22(d, 1H); 7.11 (t, 1H); 6.92 (broad s, 1H); 6.65 (d, 1H); 3.82 (s, 3H);3.51 (s, 3H); 1.90 (s, 3H).

A number of physicochemical characteristics of compounds 1-44 arecollated and given in Table 2.

TABLE 2 Physicochemical characteristics of representative compounds offormula (1) Melting Empirical Molecular point Rf Compound formula weight(C.°) (TLC) 1 C₁₅H₁₃N₃S 267.35 161.0-162.1 0.54^((a)) 2 C₁₅H₁₃N₃S•C₄H₄O₄383.41 202.5-203.2 0.54^((a)) 3 C₁₅H₁₂ClN₃S 301.79 212.2-213.50.49^((a)) 4 C₁₄H₁₉N₃S 261.39 112.6-114.7 0.53^((a)) 5 C₁₆H₁₅N₃ 249.31217.7-220.0 0.30^((a)) 6 C₁₇H₁₇N₃ 263.34 184.6-185.8 0.40^((a)) 7C₁₆H₁₅N₃ 249.31 218.0-220.0 0.30^((a)) 8 C₁₇H₁₅N₃ 261.33 143.0-144.40.52^((a)) 9 C₁₅H₁₃N₃S 267.35 177.0-178.0 0.48^((a)) 10 C₁₆H₁₅N₃OS297.37 163.0-165.0 0.45^((a)) 11 C₁₆H₁₅N₃S 281.38 117.9-120.0 0.47^((a))12 C₁₇H₁₅N₃S 293.38 90.8-91.8 0.55^((a)) 13 C₁₆H₁₆N₄O₃S₂•HCl 412.91244.0-248.0 0.40^((a)) 14 C₁₄H₁₂N₄S 268.34 187.2-188.9 0.29^((a)) 15C₁₆H₁₅N₃OS 297.37 203.0-204.7 0.47^((a)) 16 C₁₇H₁₇N₃O₂S 327.40156.4-158.3 0.50^((a)) 17 C₁₆H₁₅N₃OS 297.37 141.6-145.6 0.54^((a)) 18C₁₆H₁₅N₃S 281.38 188.4-189.8 0.50^((a)) 19 C₁₅H₁₃FN₄•2 HCl 341.22283.7-286.3 0.55^((b)) 20 C₁₅H₁₃ClN₄ 284.75 153.6-156.0 0.61^((a)) 21C₁₅H₁₄N₄•HCl 286.76 164.0-166.0 0.50^((a)) 22 C₁₄H₂₀ClN₄•2HCl 317.22276.9-278.3 0.50^((a)) 23 C₁₃H₁₃N₅•2HCl 312.20 318.0-322.0 0.54^((b)) 24C₁₃H₁₃N₅•HBr 320.19 197.0-199.0 0.54^((b)) 25 C₁₇H₁₆N₄O₂•2HCl 381.26284.0-288.0 0.20^((a)) 26 C₁₆H₁₄N₄ O₂ 294.31 271.5-274.3 0.59^((d)) 27C₁₆H₁₄N₄•2HCl 335.24 162.0-168.0 0.35^((a)) 28 C₁₆H₁₄N₂O 250.30204.8-205.9 0.24^((a)) 29 C₁₅H₁₃N₃ O 251.28  171.2-173.4° 0.35^((a)) 30C₁₅H₁₂ClN₃O 285.73 183.6-185.1 0.58^((b)) 31 C₁₆H₁₂F₃N₃O 319.29157.9-159.2 0.64^((a)) 32 C₁₆H₁₂F₃N₃O 319.29 179.2-181.0 0.59^((b)) 33C₁₅H₁₂FN₃O 269.27 157.9-159.2 0.64^((c)) 34 C₁₅H₁₂Cl₂N₃O 320.17182.0-184.0 0.73^((c)) 35 C₁₅H₁₂Cl₂N₄ 319.19 207.4-209.0 0.38^((c)) 36C₁₆H₁₄F₃N₄•HBr 399.20 284.3-285.4 0.62^((b)) 37 C₁₆H₁₆N₄ O 280.33190.5-192.8 0.13^((a)) 38 C₁₅H₁₄FN₄•HBr 349.21 266.8-269.0 0.58^((b)) 39C₁₆H₁₆N₄ 264.33 154.0-158.0 0.40^((c)) 40 C₁₃H₁₂N₄S 256.33 166.7-169.10.31^((a)) 41 C₁₇H₁₅N₃O 277.32 137.4-138.9 0.63^((b)) 42 C₁₅H₁₃N₃ O251.28 176.3-177.8 0.44^((a)) 43 C₁₇H₁₈N₄O•2HCl 367.27 253.1-254.70.27^((a)) 44 C₁₇H₁₈N₄O 294.35 205.6-207.1 0.48^((b)) ^((a))Eluent:85/25/1/2 CHCl₃/MeOH/NH₃/H₂O; ^((b))Eluent: 5/2/2 n-butanol/AcOH/H₂O;^((c))Eluent: 73/25/2 CHCl₃/MeOH/NH₃; ^((d))Eluent: 4/4/2CHCl₃/MeOH/NH₃.

Other representative examples of compounds of Formula (I) are listedbelow:

N-[2-(3-methylphenyl)benzothiazol-5-yl]acetamidine;

N-[2-(4-methylphenyl)benzothiazol-5-yl]acetamidine;

N-[2-(2-fluorophenyl)benzothiazol-5-yl]acetamidine;

N-[2-(3-fluorophenyl)benzothiazol-5-yl]acetamidine;

N-[2-(4-fluorophenyl)benzothiazol-5-yl]acetamidine;

N-[2-(2-chlorophenyl)benzothiazol-5-yl]acetamidine;

N-[2-(3-chlorophenyl)benzothiazol-5-yl]acetamidine;

N-[2-(4-chlorophenyl)benzothiazol-5-yl]acetamidine;

N-[2-(3,4-dichlorophenyl)benzothiazol-5-yl]acetamidine;

N-[2-(4-trifluoromethylphenyl)benzothiazol-5-yl]acetamidine;

N-[2-(1-Methyl-1H-pyrrol-2-yl)benzothiazol-5-yl]acetamidine;

N-(2-Furan-2-ylbenzothiazol-5-yl)acetamidine;

N-(2-Furan-3-ylbenzothiazol-5-yl)acetamidine;

N-(2-phenylethylbenzothiazol-5-yl)acetamidine;

N-(2-Pentylbenzothiazol-5-yl)acetamidine;

N-[2-(4-fluorophenyl)benzothiazol-6-yl]acetamidine;

N-[2-(3-fluorophenyl)benzoxazol-5-yl]acetamidine;

N-[2-(4-fluorophenyl)benzoxazol-5-yl]acetamidine;

N-[2-(2,4-difluorophenyl)benzoxazol-5-yl]acetamidine;

N-[2-(3,4-difluorophenyl)benzoxazol-5-yl]acetamidine;

N-[2-(2-chlorophenyl)benzoxazol-5-yl]acetamidine;

N-[2-(3-chlorophenyl)benzoxazol-5-yl]acetamidine;

N-[2-(2-methoxyphenyl)benzoxazol-5-yl]acetamidine;

N-[2-(3-methoxyphenyl)benzoxazol-5-yl]acetamidine;

N-[2-(4-methoxyphenyl)benzoxazol-5-yl]acetamidine;

N-[2-(2,4-dimethoxyphenyl)benzoxazol-5-yl]acetamidine;

N-[2-(2-methylphenyl)benzoxazol-5-yl]acetamidine;

N-[2-(3-methylphenyl)benzoxazol-5-yl]acetamidine;

N-[2-(4-methylphenyl)benzoxazol-5-yl]acetamidine;

N-(2-benzylbenzoxazol-5-yl)acetamidine;

N-(2-styrylbenzoxazol-5-yl)acetamidine;

N-(2-phenylethylbenzoxazol-5-yl)acetamidine;

N-[2-(2-fluorophenyl)benzoxazol-6-yl]acetamidine;

N-[2-(3-fluorophenyl)benzoxazol-6-yl]acetamidine;

N-[2-(4-fluorophenyl)benzoxazol-6-yl]acetamidine;

N-[2-(2-chlorophenyl)benzoxazol-6-yl]acetamidine;

N-[2-(3-chlorophenyl)benzoxazol-6-yl]acetamidine;

N-[2-(4-chlorophenyl)benzoxazol-6-yl]acetamidine;

N-[2-(3,4-dichlorophenyl)benzoxazol-6-yl]acetamidine;

N-[2-(3-trifluoromethylphenyl)benzoxazol-6-yl]acetamidine;

N-[2-(4-trifluoromethylphenyl)benzoxazol-6-yl]acetamidine;

N-[2-(2-methoxyphenyl)benzoxazol-6-yl]acetamidine;

N-[2-(3-methoxyphenyl)benzoxazol-6-yl]acetamidine;

N-[2-(4-methoxyphenyl)benzoxazol-6-yl]acetamidine;

N-[2-(2,4-dimethoxyphenyl)benzoxazol-6-yl]acetamidine;

N-[2-(2-methylphenyl)benzoxazol-6-yl]acetamidine;

N-[2-(3-methylphenyl)benzoxazol-6-yl]acetamidine;

N-[2-(4-methylphenyl)benzoxazol-6-yl]acetamidine;

N-[2-(3-fluorophenyl)-3H-benzimidazol-5-yl]acetamidine;

N-[2-(2-chlorophenyl)-3H-benzimidazol-5-yl]acetamidine;

N-[2-(3-chlorophenyl)-3H-benzimidazol-5-yl]acetamidine;

N-[2-(4-trifluoromethylphenyl)-3H-benzimidazol-5-yl]acetamidine;

N-[2-(3-methoxyphenyl)-3H-benzimidazol-5-yl]acetamidine;

N-[2-(4-methoxyphenyl)-3H-benzimidazol-5-yl]acetamidine;

N-[2-(3,4-dimethoxyphenyl)-3H-benzimidazol-5-yl]acetamidine;

4-(5-acetimidoylamino-1H-benzimidazol-2-yl)benzamide;

N-[2-(pyrrol-3-yl)-3H-benzimidazol-5-yl]acetamidine;

N-[2-(furan-2-yl)-3H-benzimidazol-5-yl]acetamidine;

N-[2-(furan-3-yl)-3H-benzimidazol-5-yl]acetamidine;

N-[2-(thien-2-yl)-3H-benzimidazol-5-yl]acetamidine;

N-[2-(thien-3-yl)-3H-benzimidazol-5-yl]acetamidine;

N-[2-(2-methoxyphenyl)quinol-6-yl]acetamidine;

N-[2-(3-methoxyphenyl)quinol-6-yl]acetamidine;

N-[2-(4-methoxyphenyl)quinol-6-yl]acetamidine;

N-[2-(2-fluorophenyl)quinol-6-yl]acetamidine;

N-[2-(3-fluorophenyl)quinol-6-yl]acetamidine;

N-[2-(4-fluorophenyl)quinol-6-yl]acetamidine;

N-[2-(2-chlorophenyl)quinol-6-yl]acetamidine;

N-[2-(3-chlorophenyl)quinol-6-yl]acetamidine;

N-[2-(4-chlorophenyl)quinol-6-yl]acetamidine;

N-[2-(3,4-dichlorophenyl)quinol-6-yl]acetamidine;

N-[2-benzylquinol-6-yl]acetamidine;

N-[2-phenylethylquinol-6-yl]acetamidine;

N-(2-phenylquinol-7-yl)acetamidine;

N-[2-(2-methoxyphenyl)quinol-7-yl]acetamidine;

N-[2-(3-methoxyphenyl)quinol-7-yl]acetamidine;

N-[2-(4-methoxyphenyl)quinol-7-yl]acetamidine;

N-[2-(2-fluorophenyl)quinol-7-yl]acetamidine;

N-[2-(3-fluorophenyl)quinol-7-yl]acetamidine;

N-[2-(4-fluorophenyl)quinol-7-yl]acetamidine;

N-[2-(2-chlorophenyl)quinol-7-yl]acetamidine;

N-[2-(3-chlorophenyl)quinol-7-yl]acetamidine;

N-[2-(4-chlorophenyl)quinol-7-yl]acetamidine;

N-[2-(3,4-dichlorophenyl)quinol-7-yl]acetamidine;

N-(3-phenylisoquinol-6-yl)acetamidine;

N-[3-(4-fluorophenyl)isoquinol-6-yl]acetamidine;

N-[3-(4-chlorophenyl)isoquinol-6-yl]acetamidine;

N-[3-(4-trifluoromethylphenyl)isoquinol-6-yl]acetamidine;

N-[3-(3,4-dichlorophenyl)isoquinol-6-yl]acetamidine;

N-[2-(2-methoxyphenyl)quinazolin-6-yl]acetamidine;

N-[2-(3-methoxyphenyl)quinazolin-6-yl]acetamidine;

N-[2-(4-methoxyphenyl)quinazolin-6-yl]acetamidine;

N-[2-(2-fluorophenyl)quinazolin-6-yl]acetamidine;

N-[2-(3-fluorophenyl)quinazolin-6-yl]acetamidine;

N-[2-(4-fluorophenyl)quinazolin-6-yl]acetamidine;

N-[2-(2-chlorophenyl)quinazolin-6-yl]acetamidine;

N-[2-(3-chlorophenyl)quinazolin-6-yl]acetamidine;

N-[2-(4-chlorophenyl)quinazolin-6-yl]acetamidine;

N-[2-(4-trifluoromethylphenyl)quinazolin-6-yl]acetamidine;

N-[2-(3,4-dichlorophenyl)quinazolin-6-yl]acetamidine;

N-(2-benzylquinazolin-6-yl)acetamidine;

N-(2-styrylquinazolin-6-yl)acetamidine;

N-(2-phenylethylquinazolin-6-yl)acetamidine;

N-(2-phenylquinazolin-7-yl)acetamidine;

N-(2-phenyl-1H-indol-5-yl)acetamidine;

N-[2-(2-methoxyphenyl)-1H-indol-5-yl]acetamidine;

N-[2-(3-methoxyphenyl)-1H-indol-5-yl]acetamidine;

N-[2-(4-methoxyphenyl)-1H-indol-5-yl]acetamidine;

N-[2-(2-methylphenyl)-1H-indol-5-yl]acetamidine;

N-[2-(2-fluorophenyl)-1H-indol-5-yl]acetamidine;

N-[2-(3-fluorophenyl)-1H-indol-5-yl]acetamidine;

N-[2-(4-fluorophenyl)-1H-indol-5-yl]acetamidine;

N-[2-(2-chlorophenyl)-1H-indol-5-yl]acetamidine;

N-[2-(3-chlorophenyl)-1H-indol-5-yl]acetamidine;

N-[2-(4-chlorophenyl)-1H-indol-5-yl]acetamidine;

N-[2-(3-trifluoromethyl)-1H-indol-5-yl]acetamidine;

N-[2-(4-trifluoromethylphenyl)-1H-indol-5-yl]acetamidine;

N-[2-(3,4-dichlorophenyl)-1H-indol-5-yl]acetamidine;

N-(1-methyl-3-phenyl-1H-indol-5-yl)acetamidine;

N-(1-methyl-3-(4-chlorophenyl)-1H-indol-5-yl]acetamidine;

N-[2-(2-methoxyphenyl)benzofuran-5-yl]acetamidine;

N-[2-(3-methoxyphenyl)benzofuran-5-yl]acetamidine;

N-[2-(4-methoxyphenyl)benzofuran-5-yl]acetamidine;

N-[2-(2-methylphenyl)benzofuran-5-yl]acetamidine;

N-[2-(2-fluorophenyl)benzofuran-5-yl]acetamidine;

N-[2-(3-fluorophenyl)benzofuran-5-yl]acetamidine;

N-[2-(4-fluorophenyl)benzofuran-5-yl]acetamidine;

N-[2-(2-chlorophenyl)benzofuran-5-yl]acetamidine;

N-[2-(3-chlorophenyl)benzofuran-5-yl]acetamidine;

N-[2-(4-chlorophenyl)benzofuran-5-yl]acetamidine;

N-[2-(3-trifluoromethyl)benzofuran-5-yl]acetamidine;

N-[2-(4-trifluoromethylphenyl)benzofuran-5-yl]acetamidine;

N-[2-(3,4-dichlorophenyl)benzofuran-5-yl]acetamidine;

N-(2-benzylbenzofuran-5-yl)acetamidine;

N-(2-styrylbenzofuran-5-yl)acetamidine;

N-(2-phenylethylbenzofuran-5-yl)acetamidine;

N-(2-phenylbenzothiophen-5-yl)acetamidine;

N-[2-(2-methoxyphenyl)benzothiophen-5-yl]acetamidine;

N-[2-(3-methoxyphenyl)benzothiophen-5-yl]acetamidine;

N-[2-(4-methoxyphenyl)benzothiophen-5-yl]acetamidine;

N-[2-(2-fluorophenyl)benzothiophen-5-yl]acetamidine;

N-[2-(3-fluorophenyl)benzothiophen-5-yl]acetamidine;

N-[2-(4-fluorophenyl)benzothiophen-5-yl]acetamidine;

N-[2-(2-chlorophenyl)benzothiophen-5-yl]acetamidine;

N-[2-(3-chlorophenyl)benzothiophen-5-yl]acetamidine;

N-[2-(4-chlorophenyl)benzothiophen-5-yl]acetamidine;

N-[2-(4-trifluoromethylphenyl)benzothiophen-5-yl]acetamidine;

N-[2-(3,4-dichlorophenyl)benzothiophen-5-yl]acetamidine;

N-(2-benzylbenzothiophen-5-yl)acetamidine;

N-(2-styrylbenzothiophen-5-yl)acetamidine;

N-(2-phenylethylbenzothiophen-5-yl)acetamidine;

N-(2-phenylquinoxalin-6-yl)acetamidine;

N-[2-(4-fluorophenyl)quinoxalin-6-yl)acetamidine;

N-[2-(4-chlorophenyl)quinoxalin-6-yl)acetamidine;

N-[2-(3,4-dichlorophenyl)quinoxalin-6-yl]acetamidine;

N-(2-benzylquinoxalin-6-yl)acetamidine;

N-(2-styrylquinoxalin-6-yl)acetamidine;

N-(2-phenylethylquinoxalin-6-yl)acetamidine;

N-(2-phenylcinnolin-6-yl)acetamidine;

N-[2-(4-fluorophenyl)cinnolin-6-yl)acetamidine;

N-[2-(4-chlorophenyl)cinnolin-6-yl)acetamidine;

N-[2-(3,4-dichlorophenyl)cinnolin-6-yl]acetamidine;

N-(2-benzylcinnolin-6-yl)acetamidine;

N-(2-styrylcinnolin-6-yl)acetamidine;

N-(2-phenylethylcinnolin-6-yl)acetamidine;

PHARMACOLOGICAL ACTIVITY

a) The inhibitory activity on the formation of NO measured as NO₂ ⁻(nitrite) and PGE₂ was studied in vitro on culture media of rabbitarticular chondrocytes stimulated with the cytokine IL-1β (1 ng/ml) for48 hours. For the preparation of the chondrocytes, the method describedby Berenbaum et al. [FEBS Letters 340, 51-55 (1994)] was followed.Briefly, fragments of cartilage removed aseptically from the articularheads of rabbit shoulder, hip and knee were finely ground and digestedat 37° C. in hyaluronidase, trypsin and collagenase solutions, giving,after filtration through sterile gauze and centrifugation at 600×g andsuitable dilution with 10% DMEM-FCS 10%, a concentration per well ofabout 1×10⁵ cells. The cells were maintained under these conditionsuntil confluent (about 15 days), the medium being replaced every 3 days.At this point, the test products dissolved in the medium were added toeach sample and, after 20 minutes, 350 μl of IL-1β were added, to give afinal concentration of 1 ng/ml. The stimulation lasted 48 hours at 37°C. (incubation in air/7% CO₂). A nitrite assay was subsequentlyperformed on the cell supernatant, as described by Green et al. [Anal.Biochem. 126, 131-138 (1982)], and of PGE₂ by RIA assay. The resultsobtained are shown in Table 3, in which is given, for a number of thecompounds that are the subject of the invention and that are alreadyillustrated in Table 1, the IC₅₀, i.e. the concentration (micromolar) ofantagonist capable of inhibiting the formation of nitrites and PGE₂ by50% relative to the control group, i.e. relative to the cells stimulatedwith IL-1β but without addition of antagonists.

TABLE 3 in vitro Activity on rabbit articular chondrocytes stimulatedwith IL-1β Inhibition % IC₅₀ (× 10⁻⁶ M) Compound Structure NO PGE₂  1

 6.5 2.4  3

IN (tox 30) 1.9  4

 6.9 6.6  5

 3.4 1.2  6

IN (tox 30) IN (tox 30)  8

47.9 2.3  9

18.0 4.2 10

IN (tox 100) 5.9 11

15.0 7.4 12

88.9 1.3 13

IN 16.2  14

IN 42.5  15

IN (tox 30) 7.4 16

IN (tox 30) IN 17

IN (tox 30) 1.3 18

 6.2 1.2 19

78   0.7 20

22.8 0.4 21

84.5 0.8 22

123   31.5  23

250   2.0 25

174   IN 26

IN IN 27

67.5 9.0 28

 7.8 0.5 29

28.6 3.2 30

IN (tox 30) 0.3 31

11.2 2.9 32

 8.1 0.6 33

47.0 13.8  34

 4.3 0.4 35

IN 0.4 36

IN IN 37

32.1 2.8 38

IN IN 39

199   9.9 40

IN 8.4 41

IN 4.0 42

42.9 5.1 L-NAME — 71.0 IN CELECOXIB — IN  0.02 Note: IN = <25%inhibitory activity at 30 × 10⁻⁶ M Tox = cellular toxicity

From the data given in Table 3, it may be deduced that some of the testcompounds that are subjects of the invention show a powerful inhibitoryeffect, at the micromolar level, on the production of NO.

The most active compounds are the benzothiazole derivatives, compounds1, 4 and 18, the indole derivative 5, the benzofuran derivative 28 andthe benzoxazole derivative 34, all having an activity of between 3 and 8micromolar.

Generally, a substitution with halogen on the phenyl group increases theactivity: see for example compound 34 (3,4-dichloro derivative relativeto the unsubstituted analogous compound, compound 29), thus there isoften a corresponding increase in the cytotoxicity that precludes theobjective evaluation of the activity of these compounds. It should alsobe noted that the NO-synthase inhibitor reference compound, L-NAME,shows activity that is about 10-fold less powerful than that of the bestcompounds that are the subject of the invention on this experimentalmodel (IC₅₀ 71 micromolar).

Some of the compounds that are the subject of the invention also inhibitthe IL-1β-induced production of prostaglandins (PGE₂) at sub-micromolarconcentrations. Thus, the benzimidazole compounds 19, 20, 21 and 35, thebenzoxazole compounds 30 and 34 and the benzofuran compound 28 inhibitthe formation of PGE₂ at concentrations (IC₅₀) of between 0.3 and 0.8micromolar.

The inhibitory activity on the production of PGE₂ by many of thecompounds that are the subject of the invention is probably at leastpartly due to their capacity to inhibit the production of NO.

In point of fact, it has been described that NO potentiates thecytokine-induced production of PGE₂ in a variety of cell systems [seefor example Watkins et al.; Br. J. Pharmacol. 121 (1997), 1482-1488].

This effect appears to be due to the amplification of the expression ofCOX-2 (Tetsuka et al.; J. Clin. Invest. 97 (1996), 2051-2056). For thecompounds that are the subject of the invention that show littleactivity as NO-production inhibitors while inhibiting the production ofPGE₂ at the submicromolar level, for instance the benzimidazolederivatives 19, 20, 21 and 35 or the benzothiazole derivatives 12, theinhibitory activity on PGE₂ production is probably associated with adirect action on the inducible cyclooxygenase enzyme.

The selective antagonist of the inducible cyclooxygenase (COX-2),Celecoxib, chosen as comparative compound, was found to be about tentimes more powerful in inhibiting the production of PGE₂ than the mostactive compounds that are the subject of the invention, whereas it wasentirely inactive as regards inhibiting the production of NO.

Some of the compounds that are the subject of the invention alsodemonstrated inhibition of the expression (mRNA) of IL-6 in isolatedhuman chondrosarcoma cells (SW 1353) stimulated with IL-1β. In practice,the RNA extracted from the cells was back-transcribed to c-DNA by meansof a thermocycler (BioRad—“iCycler”) and subsequently amplified via theReal Time PCR technique using a probe and a primer specific for IL-6,from the company Applied Biosystem, and the thermocycler 7000 SequenceDetection System (Applied Biosystem).

Using this technique, for example, compounds 5, 8, 9, 18, 27, 28 and 29were found to inhibit the expression of IL-6 in SW 1353 cells stimulatedfor 6 hours with IL-1β with an IC₅₀ of between 1.5 and 6 micromolar. Thecapacity of IL-6 to inhibit the expression of messenger RNA may beconsidered as large, since the increase in the expression of thiscytokine is associated with the physiopathology of various humandiseases, for instance Crohn's disease, as described previously.

Some of the compounds that are the subject of the invention, whichshowed the strongest activity in the in vitro tests describedhereinabove, were evaluated “in vivo” in rats on experimental models ofinflammation and hyperalgesia induced by Zymosan. This is a phlogogenicagent, consisting of a protein-glycoside complex, extracted from thecell walls of raw yeast, which is capable of inducing rapiddegranulation of neutrophils, an increase in the production of TNF-α,interleukin-1 (IL-1), IL-6 and stimulation of NO generation by monocytesand macrophages (ZymosaN:Merck Index XIII ed. No. 10250, p. 1818).

The experiments consisted of sub-plantar intradermal injection into theanimal of 4 mg of Zymosan suspended in 100 μl of sterile physiologicalsolution, while the test compounds were administered orally 30 minutesbefore injection of the phlogogenic agent.

Measurement of the inflammation of the injected paw and of theconsequent hyperalgesic effects was performed 2, 4 and 6 hours after theadministration of Zymosan. The oedema was evaluated as the increase involume of the injected paw within the period 0-6 hours, relative to theinitial value of the volume of the paw, i.e. before the injection ofZymosan (basal value).

The measurements of the variation of the volume of the paw were recordedusing a hydroplethysmometer (Mod. 7150, Basile, Italy), which consistsof two plastic cuvettes containing a surfactant liquid, the larger onebeing used for immersion of the paw, connected to the smaller one whichcontains a transducer capable of recording small displacements of volumeof the liquid used for the measurement. The paw is immersed in thecuvettes up to the tibiotarsal joint. The volume of liquid displaced bythe paw indicates the magnitude of the inflammation.

For each test compound, at least three doses were used (generally 10, 20and 40 mg/kg) with at least five animals per group x dose, so as to beable to calculate an ED₃₀, i.e. the dose in mg/kg capable of reducing by30% the Zymosan-induced volume increase, relative to the group ofcontrol animals, i.e. animals injected only with the phlogogenic agentand treated orally with distilled water.

The hyperalgesia induced by the intradermal administration of Zymosanwas evaluated on these animals and at the same times describedpreviously for the evaluation of the oedema, using the Randall-Selittomethod [Arch. Int. Pharmacodyn. 111, 409 (1957)].

In practice, an analgesimeter was used (Basile, Italy), which consistsin applying to the inflamed paw a weight in the form of a rounded-tippedcone, on which the applied force is gradually increased. When the animalmakes a noise following the pain stimulus, the operator blocks the punchand records the force, expressed in grams, which was applied to the paw(the cut-off value is 500 grams). The difference in the mechanical painthreshold between the basal value (generally about 230-250 grams) andthat recorded at the indicated times after injection of the phlogogenicagent, generally 130-140 g for the control animals 6 hours afterinjection of the phlogogenic agent, is defined as mechanicalhyperalgesia. In this case also, an ED₃₀ was calculated, i.e. the dosein mg/kg capable of increasing the pain threshold by 30% (mechanicalhyperalgesia) in the animals treated with the test compounds relative tothe group of control animals.

The results thus obtained are given in Table 4, which presents the ED₃₀values for the anti-inflammatory and anti-hyperalgesic activity for anumber of compounds that are the subject of the invention, compared withthose obtained with Celecoxib and L-NAME.

TABLE 4 Anti-inflammatory and analgesic activity (measured in the range0-6 hours) in rat paw injected with Zymosan. (ED₃₀ mg/kg os) AnalgesicAnti- activity inflammatory (mechanical Mean activity anti- (Oedema +Compounds (oedema) hyperalgesia) Analgesia) 1 12.6 6.7 9.7 5 39.4 19.329.4 8 19.8 11.8 15.8 9 33.9 31.3 32.6 27  24.6 13.0 18.8 28  20.8 24.422.6 Celecoxib 79.4 69.2 74.3 L-NAME IN IN IN Note: the compound L-NAMEwas entirely inactive up to the maximum dose administered (50 mg/kg).

As may be deduced from the data given above in Table 4, many of thecompounds that are the subject of the invention, for instance thebenzothiazole derivatives, compounds 1 and 9, the indole derivative,compound 5, the quinoline derivative, compound 8, the quinazolinederivative, compound 27, and the benzofuran derivative, compound 28,show powerful anti-inflammatory and anti-hyperalgesic action even whenadministered orally, indicating that they therefore have goodbioavailability. On average, using the compounds illustrated, andconsidering overall both the anti-oedema-generating activity and theanalgesic activity, an activity about 2 to 7 times higher than that ofthe selective COX-2 antagonist Celecoxib is obtained.

The NO-synthase antagonist L-NAME was inactive up to the maximum dosetested (50 mg/kg) since, besides having an intrinsic activity that isgenerally lower than that of the compounds that are the subject of theinvention, it may probably also be poorly absorbed via the oral route.

In conclusion, by means of the combined action of inhibition of theproduction of NO and, indirectly, that of the prostaglandin PGE₂, alongwith the action of inhibiting the expression of pro-inflammatorycytokines such as IL-6, many of the compounds that are the subject ofthe invention show in vivo an anti-inflammatory and analgesic effectthat is greater than both that of Celecoxib, i.e. a powerful andselective antagonist of inducible cyclooxygenase (COX-2), and than thatof L-NAME, an NO-synthase antagonist.

1. A compound represented by the general formula (I) indicated below andin which:

G₁ and G₂ are independently selected from hydrogen and the amidinesubstituent of formula Q, provided that, for each compound of formula(I), only one of the two substituents G₁ or G₂ is the amidinesubstituent of formula Q; the amidine substituent of formula Q isrepresented by the structure given below, in which R is methyl: Amidinesubstituent of formula Q:

W is independently: a bond, an unsubstituted carbon atom, or a carbonatom substituted with a methyl, an unsubstituted nitrogen atom (═N—); Yis an unsubstituted carbon atom, a carbon atom substituted with amethyl, or an unsubstituted nitrogen atom (═N—); X is a substituted orunsubstituted carbon atom (═CR₁— or ═CH—), a unsubstituted nitrogen atomsubstituted with a hydrogen or a methyl, a sulfur atom (—S—) or anoxygen atom (—O—), provided that the substituents W, Y and X give rise,suitably in combination, to 9- or 10-membered bicyclic heteroaromaticderivatives containing up to 2 hetero atoms in the same ring; R₃ and R₄are both hydrogen; Z is an aryl or heteroaryl group, a linear orbranched C₃-C₆ alkyl or alkenyl chain, a C₁-C₄ alkyl-aryl group oralkenylaryl group, or a C₁-C₄ alkyl-heteroaryl group in which the arylgroup is a phenyl which is unsubstituted or substituted with one or moresubstituents independently selected from halogen, trifluoromethyl,hydroxyl, nitro, cyano, carboxyl, carboxamido, carbonyl, thio,methylthio, methanesulfonyl, methanesulfinyl, sulfonamido,trifluoromethoxy, C₁-C₆ alkoxy and C₁-C₆ alkyl, and the heteroaryl groupis a 5- or 6-atom heterocyclic aromatic ring containing one or morehetero atoms, which is unsubstituted or substituted with one or moresubstituents independently selected from halogen, trifluoromethyl,hydroxyl, nitro, cyano, carboxyl, carbonyl, thio, methylthio,methanesulfonyl, methanesulfinyl, trifluoromethoxy, C₁-C₆ alkoxy andC₁-C₆ alkyl; the C₁-C₄ alkyl-aryl group is a linear or branched,saturated or unsaturated C₁-C₄ hydrocarbon chain substituted with anaryl group. When the C₁-C₄ chain is unsaturated, it is intended tocontain only one substituted or unsubstituted double bond; substituentsfor the aryl group are independently selected from the groups definedabove as substituents for the aryl group; the C₁-C₄ alkyl-heteroarylgroup is a linear or branched, saturated or unsaturated C₁-C₄hydrocarbon chain substituted with a substituted or unsubstitutedheteroaryl group; when the C₁-C₄ chain is unsaturated, it is intended tocontain only one substituted or unsubstituted double bond; the term“heteroaryl” means any of the heterocyclic nuclei defined above; thecompounds of formula (I) being either in free base form or aspharmaceutically acceptable salts. 2-3. (canceled)
 4. The compoundaccording to claim 1, wherein X is a nitrogen atom substituted withhydrogen or with methyl.
 5. The compound according to claim 1, whereinX, is an oxygen atom.
 6. The compound according to claim 1, wherein Y isan unsubstituted carbon atom (═CH—) or a carbon atom substituted withmethyl instead of a nitrogen atom (—N═) X, is a nitrogen atomsubstituted with hydrogen or with methyl.
 7. The compound according toclaim 6 wherein X, is an oxygen atom.
 8. The compound according to claim6, wherein X, is a sulfur atom.
 9. The compound according to claim 1,wherein W is an unsubstituted carbon atom (═CH—) or a carbon atomsubstituted with methyl, and X, is an unsubstituted nitrogen atom (═N—).10. The compound according to claim 9, wherein Y is an unsubstitutedcarbon atom (═C—) or a carbon atom substituted with a methyl.
 11. Thecompound according to claim 9, wherein X is an unsubstituted carbon atom(═CH—) or a carbon atom substituted with methyl.
 12. The compoundaccording to claim 9, wherein W is an unsubstituted nitrogen atom (═N—),and is an unsubstituted carbon atom (═CH—) or a carbon atom substitutedwith methyl.
 13. The compound according to claim 9, wherein W, is anunsubstituted nitrogen atom (═N—), and is an unsubstituted carbon atom(═CH—).
 14. The compound according to claim 1, in the form ofpharmaceutically acceptable salts, chosen from hydrochloride,hydrobromide, sulfate, hydrogen sulfate, methanesulfonate, maleate,citrate, fumarate and succinate.
 15. A method of treating pathologicalconditions associated with inflammatory or autoimmune phenomena,comprising administering the compound according to claim 1, or of apharmaceutically acceptable salt thereof.
 16. A method of treatingconditions comprising administering the compound according to claim 1,or of a pharmaceutically acceptable salt thereof, to inhibit theproduction of nitric oxide (NO) and of interleukin-6 (IL-6).
 17. Apharmaceutical preparation comprising, as active substance, at leastcompound according to claim 1, or a pharmaceutically acceptable saltthereof, and optionally a pharmaceutically acceptable vehicle.
 18. Amethod for the therapeutic treatment of pathological conditionsassociated with inflammatory and autoimmune phenomena comprisingadministering the pharmaceutical preparation according to claim
 17. 19.A method for controlling and preventing degenerative articular diseasessuch as rheumatoid arthritis and osteoarthritis comprising administeringthe pharmaceutical preparation according to claim
 17. 20. A method forthe analgesic treatment of pain of articular or neuropathic origincomprising administering the pharmaceutical preparation according toclaim
 17. 21. A method for the therapeutic treatment of inflammatorydiseases of the gastrointestinal tract, for instance ulcerative colitisand Crohn's disease comprising administering the pharmaceuticalpreparation according to claim
 17. 22. Pharmaceutical The pharmaceuticalpreparation according to claim 17, comprising pharmaceuticallyacceptable inactive ingredients chosen from the group consisting ofvehicles, binders, flavourings, sweeteners, disintegrants, preservingagents, humectants and mixtures thereof, or ingredients to facilitaterectal, transdermal or transmucosal absorption or that allow controlledrelease of the active substance over time, and also ingredients suitablefor parenteral use, for instance intravenous, intramuscular,subcutaneous, intradermal and intra-articular administration, in whichcases the salified compounds as described in claims 1 and 14 arepreferably used.
 23. A process for preparing a compound of generalformula (I) in which W, Y, X, G₁, G₂, R₃ and R₄ have the meaning givenin claim 1, which comprises the operations of reacting a compound offormula (II)

in which W, Y, X, Z, R₃ and R₄ are defined as for the compounds offormula (I), while G′₁ and G′₂ are independently selected from:hydrogen, halogen, hydroxyl, C₁-C₄ alkoxy, C₁-C₄ alkyl, and the aminegroup (—NH₂), provided that, for each compound of formula (II), only oneof the two substituents G′₁ or G′₂ is an amine group (—NH₂), with acompound of formula (III)

in which R is as defined above in claim 1 for the amidino substituent offormula Q and L is a leaving group, such as an alkoxy group (ethoxy ormethoxy), an alkylthio group (RS—; thiomethyl or thiomethylnaphthyl) oran arylthio group (Ar—S; thiophenyl), in a suitable solvent such asalcohol, acetonitrile, N,N-dimethylformamide (DMF) or tetrahydrofuran(THF), at temperatures of between 0° C. and 50° C.; optionally, theconversion of a compound of formula (II) into a compound of formula (I)possibly being completed by the removal of any protecting groupspresent; the compounds of formula (I) are finally recovered from thereaction mass, purified via conventional methods and isolated inunmodified form or in the form of pharmaceutically acceptable salts.